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\section{Notes on Individual Clouds and Associated Objects}
\subsection{Local Arm Clouds }

\paragraph{Clouds 4 and 9} lying in the velocity range $-6$ to
$-16$~km~s$^{-1}$ (see Figure 1) are quite anomalous, since negative
velocities cannot result from circular Galactic rotation in the third
quadrant. The forbidden velocity is most plausibly the result of star
formation and the large-scale acceleration of gas by OB winds and
supernovae, possibly similar to those to which the ring-like structure
observed towards the nearby Mon~R1 region has been attributed (Kutner
et al. 1979). The projected position of the CO emission in cloud
9, as it is traced towards less negative velocities, corresponds to the
strong emission around the young stellar object VY~Mon and the IC~446
reflection nebulae (Casey and Harper 1990). VY~Mon (also known as
HRB~202n, AFGL~951S, and IRAS~06283+1028) is the brightest star of a
cluster of emission-line stars with a spectral type between O9e and B8e
(Casey and Harper 1990, and references therein).  VY~Mon is highly
reddened~($A_{\rm v}~\cong~7.4$ mag), indicating foreground dust. 

There is weak, fragmented CO emission tracing an arc between clouds 9 and
4 (see Figure 2a) coinciding with a similar  H\,{\sc i}  \normalsize feature
subtending about 3$^{\circ}$ in $\ell$ and $b$ (Kutner et al.
1979). This weak band of CO at negative velocities corresponds well to the
dimensions of the reddened, faint emission of LbN~887, and LbN~895 at
$\ell=199.5^{\circ}$ $b=+0.07^{\circ}$ and $\ell=200.8^{\circ}$
$b=+0.46^{\circ}$ respectively. The central position of LbN~895 coincides
with a hole in the CO at velocities $>+4$~km~s$^{-1}$. 

\paragraph{Cloud 7} is an extension to the Mon~R1 region (see Figure 2a, 2b 
and 6b) and comparable in mass to cloud 11 (see below). A possible embedded
expanding shell is centred at $\ell=199.6^{\circ}$ $ b=+1.0^{\circ}$,
with a radius of 0.35$^{\circ}$ (5.5~pc at $d~=0.9~$kpc). The projected
edges of the structure correspond to strong CO emission, IRAS point
sources, and increased extinction on the POSS plates. The expansion
velocity is 4.4~km~s$^{-1}$, implying an expansion time scale of 1.2
$\times 10^6$~yr. Coincident with the centre is a faint, reddened emission
nebula (LbN~889) with an estimated radius of 0.27$^\circ$ (Lynds 1965). 


\paragraph{Cloud 10 and Cloud~11} form a partial ring of CO
emission associated with the Mon~R1 region (see Figures 6a and 6b). It was
first observed in the CO line by Kutner \it{et~al.} \rm (1979), who
reported two distinct velocity features at $-$1 to +1~km~s$^{-1}$ and +3
to +5~km~s$^{-1}$, with optical features observed at corresponding radial
velocities (see Figures 2a, 2b, 6a and 6b). Cloud 10 is spatially distinct
from cloud 11 and has a number of reflection nebulae, VDB~76, 77, and 78
associated with the strongest emission.  Cloud 11 is associated with the
open clusters NGC~2245 and NGC~2247 (see Figure~6b), extends over a larger
area than Cloud 10, and is considerably more massive (see Table 1). 

Kutner et al. suggested that either stellar winds or a supernova
in the recent past (expansion age of about $1-3 \times 10^{6}$~yrs) were
responsible for the ring-like appearance of both the optical and CO
features. Such an event might explain the velocity separation of these two
neighboring clouds. At finer angular resolution cloud 10 resolves into
three distinct emission peaks, each associated with an optical nebulosity
(Kutner et al. 1979). Cloud 11 resolves into larger number of
clumps, some relating to the open clusters NGC~2245 and NGC~2247, and to
the bright reddened nebulosity LbN~899, which coincides with the emission
peak at $\ell=201.5^{\circ}$ $b=+1.8^{\circ}$ (Lynds 1965). This strong CO
emission coincides with an optical nebulosity on the POSS plates and with
a stronger maximum (4.6~K) in 1420~MHz continuum emission than is observed
towards the Mon Loop SNR (4.4~K, Reich and Reich 1986). The rest of the CO
emission closely traces the extent of the dark cloud L1605. 


\paragraph{Cloud~12} (see Figure~2a) is receding from cloud~13 (see
Figure~2b) at a mean velocity of $4.0~$km~s$^{-1}$. NGC~2259 appears at
the `sharp' edge of the strong emission of cloud 13, and the emission-free
cavity (see Figure 6b). Trumpler's (1930) distance estimate of 3.9~kpc,
based on angular diameter and appearance alone is unreliable. Generally
his distance estimates should be considerably reduced (Bok, Olmstead and
Boutelle 1949). Adopting a distance to the cluster of around 1.0~kpc would
help explain the physical structure and kinematics of clouds 12 and 13 . 



\paragraph{Cloud 15} is a bridge of weak emission seemingly connecting the
Mon~R1 and the Cone Nebula regions (clouds 11 and 16, see Figure~2b). The
CO emission closely traces the dark nebula projected against the bright
 H\,{\sc ii}  \normalsize region S~273 which is visibly in front of the cloud
16 (P\'{e}rez 1991).  We suspect, therefore, that the apparent connection
in CO of the Mon~R1 region (clouds 10 and 11) with the Cone cloud (cloud
16) is a kinematic and line of sight coincidence. 

\paragraph{Cloud 16 and Cloud~13} form a massive complex of molecular
clouds (see Figure 2b) extending 70~pc along the Galactic plane at a
distance of 0.95~kpc (Pe\'rez et al. 1987). Cloud 16, often
referred to as the Cone cloud, is the progenitor to the young open cluster
NGC~2264 (age $\sim 5 \times 10^{6}$~yrs), the Cone Nebula and the O7 star
S~Mon. It has been extensively studied with higher angular resolution,
revealing molecular outflows and young stellar objects, indications that
large regions of the Cone cloud are undergoing star formation (Margulis
and Lada 1986, Margulis et al. 1988, Margulis et al. 1989, Lada \it{et
al.} \rm 1992 and Wolf-Chase, Walker and Lada 1995). A number of
 H\,{\sc ii}  \normalsize regions, S~273, Col~147/148 (Dubout-Crillon 1976),
and bright nebulae (Lynds 1965) coincide with the position of the cluster,
an indication that the young hot stars are ionizing the nearby gas. 

\paragraph{Cloud 17} is an elongated string of emission associated with
NGC~2261 (the Fan Nebula, see Figure 6b). NGC~2261 is illuminated by the
variable star R~Mon, a Herbig Ae/Be star, which is thought to be
surrounded by an interstellar torus.  Staude and Els\"{a}sser (1993)
proposed that the star produces a fast wind which is collimated by the
surrounding interstellar material.  Cant\'{o} et al. (1981) made
a CO survey of 37 square arc minutes around NGC~2261 and the Herbig-Haro
object HH---39. With a 4$\sigma$ detection limit of $\sim$1~K they
described two small clouds at +9.4 and +7.5~km~s$^{-1}$. With increased
area coverage and sensitivity we detect a string of clumps extending at
least 22~pc along the Galactic plane (see Figures 2b and 6b). The
velocities observed for this feature range from +9.1~km~s$^{-1}$ at the
position of NGC~2261, to +4.8~km~s$^{-1}$, a uniform velocity gradient of
+0.2~km~s$^{-1}$pc$^{-1}$ along its length. The positive sign indicates
that the inferred angular velocity vector of the cloud's rotation is
parallel to the angular velocity vector of the Galactic disk. The
strongest emission corresponds to slightly increased extinction on the
POSS plates. 


\paragraph{Cloud 18, cloud 19 and cloud 20} appear to surround the open
cluster NGC~2254, a strong, fairly-rich concentration of 20 stars of
comparable brightness (Lyng\aa \hspace*{0.06in} 1987), whose age is
approximately $6 \times 10^8$~yrs (Vogt and Moffat 1975).  The three
clouds have velocities ranging from $-$3.1~km~s$^{-1}$ to +9.4~km~s$^{-1}$
(see Table 2), which are normally attributed to local emission.  However,
the photometrically derived distance to NGC~2254 of $\sim$2.2~kpc (Kiral
1969) does not compare well to the distance of $\sim 0.9$~kpc we adopted
for these Local arm clouds. Clouds 18, 19 and 20 could be receding from
the old cluster, in which case their velocities would not be good
indicators of their distances. Furthermore, a small open cluster, Basel 7,
whose distance is reported to be 1.6~kpc (Lyng\aa \hspace*{0.06in} 1987),
is adjacent to cloud 18 (see Figure 6b).  Its age is $\sim$6$\times
10^8$~yrs (Vogt and Moffat 1975), comparable to that of NGC~2254.  From
his photometric investigation of 21 main sequence stars in NGC~2254, Kiral
(1969) claimed that interstellar absorption is only appreciable beyond
0.8~kpc. This provides a further rough estimate of the distance to cloud
19, which is in the line of sight towards NGC~2254 and would therefore be
a foreground object. Present data are insufficient to determine whether
clouds 18 and 20 are similarly foreground, or whether they are more
distant and receding from the cluster. 

All three clouds lie on enhanced radio continuum emission
of the Monoceros Nebulosity (Graham \it{et~al.} \rm 1982) which is also
prominent in H$\alpha$ (Meaburn 1968) and has been interpreted as an SNR
(Lozinskaya 1972). 

\subsection{Inter-arm Clouds}

\paragraph{Cloud 21} is a feature representing three weak
emission peaks (see Figures 6b and 6c) adjacent to the A0 stars 13~Mon
(HD~46300, labelled \it{B} \rm in Figure 6c) and 14~Mon (HD~46642, labelled 
\it{C} \rm in Figure 6c), and bright nebulae reported by Lynds (1965). Weak
emission is detected over a wide velocity range from ~$+10$ to $+30$
km~s$^{-1}$, kinematically encompassing the stars. 

\paragraph{Cloud 23} closely corresponds to the extent of Lynds dark
nebula L1626 (Lynds 1962). The strongest emission, at
 $\ell=206.5^{\circ}$ $b=+1.3^{\circ}$ (see Figure 2b), corresponds to the
centre of the nebula 0641+06 identified by Graham et al. (1982).
They describe radio continuum emission with spectral indices approaching
those expected of an optically thin  H\,{\sc ii}  \normalsize region. The
centre of the nebula is reported as $\ell=206.4^{\circ}$ $b=+1.4^{\circ}$,
appearing approximately circular in shape with a diameter of 0.5$^{\circ}$
(Graham et al. 1982). The illuminating star is apparently the
O6e star HD~48099, which is 0.6$^{\circ}$ (15~pc at an assumed
distance of 1.4~kpc) away at $\ell=206.2^{\circ}$ $b=+0.8^{\circ}$
(labelled \it{D} \rm in Figure 6c). 

\paragraph{Cloud 24} is a partial ring of faint CO
emission surrounding the open cluster NGC~2252 (see Figure 6b), a
medium-rich cluster of 30 stars associated with some visible
nebulosity (Lyng\aa \hspace*{0.06in} 1987). Cloud 24 represents the
mean profile and total mass of several weak features.  The weak
emission components range in velocity from +7.4 to +17~km~s$^{-1}$,
giving kinematic distance estimates of 0.8 to 2.0~kpc. The
photometrically-derived distance of 1.6~kpc for NGC~2252 corresponds
to a position between those estimated for the individual CO
components.

\paragraph{Cloud 25} is a complex region of emission
which consists of 2 main components, an arc and a bright clump (see
Figure 2c).  Plaskett's star (HD~47129, labelled \it{E} \rm in Figure 6c), a
bright O7e~---~O8f star, is adjacent to the strong emission peak of the
clump (see Figure 6c). The radial velocity of the clump is
+22.3~km~s$^{-1}$, comparable to +25~km~s$^{-1}$ for
HD~47129. Col~106, a small open cluster of $\sim$20 stars at a
projected position is adjacent
to the clump and HD~47129 (Lyng\aa \hspace*{0.06in} 1987). 

The arc of emission is an expanding partial ring adjacent to the positions
of HD~48099 with a spectral type of O6e (labelled \it{D} \rm in Figure
6c), and HD~47756 with a spectral type of B8 (labelled \it{F} \rm in
Figure 6c). Photometry gives an estimated distance to HD~48099 of 1.4~kpc
(Wallerstein and Jacobsen 1976), which is in good agreement to the
kinematically-estimated distance of 1.7~kpc to cloud 25.  A small open
cluster, Col~111 (Lyng\aa \hspace*{0.06in} 1987), lies on the edge of the
arc (see Figure 6c). 

\subsection{Perseus Arm Clouds}

\paragraph{Cloud 27} at an estimated distance of 3.8~kpc, extends
approximately 100~pc along the Galactic plane. It has a mass of
1.8--4.6$\times 10^{4} M_{\sun}$, which makes it comparable in mass to the
local GMCs reported here, for example the Cone cloud (cloud 16). 

\paragraph{Cloud 28} is an arc of emission which is accompanied by diffuse
extended CO filaments (see Figure 2c).  Analysis of the individual channel
maps reveals an expanding partial ring with a central radial velocity of
approximately $+20$~km~s$^{-1}$. The B5 star HD~44173 (labelled \it{A} \rm
in Figure 6c) has a radial velocity of +19~km~s$^{-1}$, and is adjacent to
the strongest emission. The kinematically estimated distance to cloud 28
is 2.8~kpc. 

\paragraph{Cloud 29}, at an estimated distance of 3.4~kpc, is elongated
along the Galactic plane, with a longest dimension of 100~pc. The
luminosity-derived mass estimate of 1.0 -- 1.4$\times 10^{4} M_{\sun}$
makes cloud 29 comparable in mass to many of the local GMCs, although not
as massive as one of comparable dimensions such as cloud~16. 

\paragraph{Cloud 30} is comparable to many local GMCs with a mass of 0.7
-- 1.1$\times 10^{4} M_{\sun}$. The kinematically-estimated distance to
this cloud is 3.7~kpc. The higher spatial resolution of WB's observations
indicated that the emission is brighter here than we detect in our $8'.7$
(FWHM) beam. 

\paragraph{Cloud 31} is a massive and distant GMC which was first detected
by Blitz (1978).  It is similar to the Cone cloud in total mass (4.0 --
$8.0 \times 10^4M_{\sun}$) and projected area (approximately
$10^4$~pc$^2$). The strongest emission has a central velocity of
+32~km~s$^{-1}$, slightly higher than might be expected for a cloud within
the Perseus arm at $\ell = 203^{\circ}$ (see Figure 1). This gives a
kinematic distance estimate of 5.3~kpc. The lower velocity of a
substructure of the cloud, +28~km~s$^{-1}$, gives a more conservative
kinematic distance of 4.5~kpc.  However, these estimates may be affected
by streaming motions in the Perseus arm of up to 10~km~s$^{-1}$ (Humphreys
1976; Brand and Blitz 1993). This cloud provides our only opportunity to
compare kinematic and photometric distance estimates by its association
with Trumpler~5, an old, rich, open cluster with about 150 members
(Trumpler 1930), whose photometrically derived distance is 2.4~kpc
(Lyng\aa \hspace*{0.06in} 1987). The disagreement with the kinematically
derived distance to cloud 31 suggests the presence of significant
streaming motions. However, a line of sight coincidence cannot be ruled
out as the cluster is visibly in front of the molecular cloud. Trumpler 5
with an age of $\sim 1-8 \times 10^9$~yrs (Vogt and Moffat 1975) is the
oldest Galactic cluster within the survey region and its relationship with
cloud 31 could be a coincidence. Indeed no evidence for massive star
formation is found, none of our SIPS lie towards cloud 31. 


\paragraph{Cloud 32} is a region of weak emission
adjacent to the arc of cloud~25 (see Figure 2c).  At a radial velocity
of 34.5~km~s$^{-1}$ cloud 32 is receding from cloud 25 with a mean
velocity of 12.5~km~s$^{-1}$. Although the kinematically-estimated
distance to cloud 25 is in good agreement with the photometrically
estimated distance to HD~48099, the radial velocities of HD~48099
and HD~47756, +31 and +35~km~s$^{-1}$, respectively, compare better to
the radial velocity of cloud 32 than to that of cloud 25.


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\end{document}
