ANTARCTIC BRYOZOA — ROGICK 261 



The species is named in honor of Comdr. David C. Nutt, who 

 collected the Bryozoa of the expedition. 



Zoarium: This species is represented by five calcareous, ivory- 

 colored colony fragments; the three largest range from 20 to 24 mm. 

 in length (pi. 14, A). The two smallest scraps are apparently basal, 

 very much worn down and therefore of questionable identity. No 

 measurements or drawings were made from these two fragments. 

 None of the fragments is a complete, fully grown colony. The shape 

 of the most perfect and symmetrical fragment (pi. 14,A) is somewhat 

 flabellate or slablike. The other two sizable fragments are broken-off 

 pieces neither basal nor terminal but cut at the branching zone, 

 irregular and rather tapeUke. Nodes occur about 3 to 6 mm. apart. 

 They are neither flexible nor real joints, simply slightly depressed 

 bands from which orifices are absent (pi. 14,A,B). There are 4 to 8 

 linear rows along an internode (between nodes) and 8 to 17 rows 

 across one face of an internode (from side to side). Although the 

 colony is bilaminate and most of the zooecia open out on the two 

 flat faces, a few zoids open out on the thin edge also (pi. 14, G). 

 Colony surface is pitted (pi. 14,B). The large holes are the orifices, 

 the small ones are channeled frontal pores. The frontal pores are 

 0.014-0.058 mm. (average 0.040 mm.) across. 



Zooecia: Zooecia are long and narrow. Length, based on external 

 measurements, 1.08-2.059 mm. (average 1.670 mm.); width 0.238- 

 0.360 mm. (average 0.285 mm.). 



The zooecial surface is sometimes shghtly ridged, especially about 

 the orifice (pi. 14,E,H) and near the mucros (pi. 14, C). The side 

 and back walls of the zooecia are thin. The front wall is channeled 

 and 0.202-0.403 mm. (average 0.249 mm.) thick. The lateral walls 

 have the customary appearance of other species in this genus, namely, 

 a few large multiporous rosette plates along their raidregion and one 

 or two rows of small single pores along their frontal borders (pi. 15,H). 



Avicularia: The internal avicularium cannot be recognized as 

 such until the zooecium is tipped forward in order to look down into 

 the orifice. The internal avicularium is placed transversely across the 

 inner lower border of the orifice so that part of its side wall shows 

 from the outside (pi. 14,E,F,H,K). It is sometimes slanted a bit to 

 the left, sometimes to the right, so that in front view it is not hori- 

 zontal. Its beak is slightly hooked. Measurements of the internal 

 avicularium: total length 0.202-0.216 mm. (average 0.209 mm.); total 

 width 0.086-0.144 mm. (average 0.109 mm.); beak length 0.130- 

 0.158 mm. (average 0.143 mm.). 



The external avicularium is directed obliquely downward at a con- 

 siderable angle away from the orifice proximal border. It is near the 

 midline (pi. 14,F-H,K), cradled between two mucros. The posterior 



