We present 107 maps of continuum emission at 350 \mu m from Galactic molecular clumps .
Observed sources were mainly selected from the Bolocam Galactic Plane Survey ( BGPS ) catalog , with 3 additional maps covering star forming regions in the outer Galaxy .
The higher resolution of the SHARC-II images ( 8.5″Â beam ) compared with the 1.1 mm images from BGPS ( 33″Â beam ) allowed us to identify a large population of smaller substructures within the clumps .
A catalog is presented for the 1386 sources extracted from the 350 \mu m maps .
The color temperature distribution of clumps based on the two wavelengths has a median of 13.3 K and mean of 16.3 \pm 0.4 K , assuming an opacity law index of 1.7 .
For the structures with good determination of color temperatures , the mean ratio of gas temperature , determined from NH _ { 3 } Â observations , to dust color temperature is 0.88 and the median ratio is 0.76 .
About half the clumps have more than two substructures and 22 clumps have more than 10 .
The fraction of the mass in dense substructures seen at 350 \mu m compared to the mass of their parental clump is \sim 0.19 , and the surface densities of these substructures are , on average , 2.2 times those seen in the clumps identified at 1.1 mm .
For a well-characterized sample , 88 structures ( 31 % ) exceed a surface density of 0.2 g cm ^ { -2 } , and 18 ( 6 % ) exceed 1.0 g cm ^ { -2 } , thresholds for massive star formation suggested by theorists .