226 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



The measurements for the Antarctic (Marguerite Bay) specimens 

 (table 1) are larger for every part when compared with measurements 

 given for Barentsia discreta by Busk, Harmer, Marcus (1937), Oka, 

 Osburn (1944), and Zirpolo. They are approached closely by figures 

 given by Verrill, and Johnston and Angel, and are exceeded in the 

 case of total combined length of calyx and stalk only by Kluge's fine 



Table 1. — Dimensions, in millimeters, of parts of Antarctic Barentsia discreta /row 



Marguerite Bay 



Part and dimension 

 Musclium length 

 Musclium diameter 

 Combined pedicel-peduncle length 

 Peduncle or pedicel diameter 

 Calyx height 



Calyx anteroposterior length 

 Pedicel, peduncle, and musclium (calyx ex- 

 cluded) combined length 

 Stolon diameter 



Arctic specimens. The total length or height of a zoid should include 

 calyx, stalk (pedicel-peduncle), and musclium. However, because 

 many of the Marguerite Bay specimens had either lost their heads or 

 because some of the calyx-topped stalks were broken away from the 

 musclium, it was not possible to get very many readings of complete, 

 intact specimens. 



On the basis of comparison of all recorded measurements for this 

 species it can be concluded that the amount of variation in size of each 

 individual part (calyx, stalk, musclium) is very considerable, for a 

 bryozoan, anyway. For example, the total height or combined length 

 of a B. discreta zoid (calyx, stalk, musclium) ranges from 1.584 mm. 

 (Harmer, 1915) to 8.755 mm. (EQuge, 1946a). The very largest 

 specimens however did come from the colder-zone waters (Arctic and 

 Antarctic), although Verrill's Bermuda specimens were good-sized and 

 larger than those reported from Tropical and Temperate Zones by 

 other authors. Since this is a species found in such widely differing 

 climatic areas and since it also occurs so near to some of our fine 

 marine laboratories, it would be an excellent species for further 

 ecological and physiological research. 



Ecology and distribution: Barentsia discreta was taken in 1948 

 in bottom dredge hauls from a depth of 35 fathoms at Station 190 on 

 Feb. 20, at Station 234 from 40 fathoms on Feb. 22, and at Station 

 243 on Feb. 22. Commander Nutt and Chief Electrician Layton 

 were the actual collectors. Water temperature in the first two sta- 

 tions was 30° F. The B. discreta from Station 243 was entangled on 





