NO. 2 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 499 



jointed at the base. Interzooecial avicularia were not observed by Canu 

 and Bassler in Galapagos specimens, but I have found several at the 

 edges of older colonies, exactly similar to that figured by Busk (plate 29, 

 fig. 3). 



The ovicell is incomplete, hood-shaped, smooth and measures 0.26 

 mm in width ; it has not previously been observed. 



Among the zooecia of the secondary layers there are high cylindrical 

 tubes with a round aperture which appear to have been a mystery to 

 other observers. Busk remarks that "The nature of these appendages 

 appears very obscure," and Canu and Bassler add "The sporadic salient 

 tubes also have an unknown zoarial function." A little dissection would 

 have solved the mystery since, on dissecting carefully to the bottom 

 of the tube, a primary aperture with its denticles is discovered. The 

 tubes are the extended peristomes of underlying zooecia, some as far 

 down as the second lower layer. Apparently the covered zooids have 

 found a method of continuing their existence by extending their peri- 

 stomes above the superficial layer. The phenomenon is to be observed, 

 even more strikingly in the new species, H. peristomata new species, 

 and in H. pilaefera Canu and Bassler (1930:422). 



The species has been found in several places in Australian waters, 

 listed for the Miocene of Australia and New Zealand, and recorded 

 for the Galapagos Islands by Canu and Bassler. 



Hancock Stations: 143-34, Wenman Island; 155-34, 432 and 450, 

 Albemarle Island; 438, Chatham Island, and 444, James Island, all 

 at the Galapagos, where it appears to be well distributed. The depth 

 range was from 20 to more than 100 fms. 



Holoporella hancocki new species 

 Plate 61, figs. 1-2 



Zoarium erect and irregularly branching dichotomously and more or 

 less in one plane, attached by a small base; the branches round, varying 

 in diameter from 4 mm near the base to 1 mm near the tips of the 

 outer branches; considerable areas of the older stems are devoid of 

 autozooecia; the broken tips of the larger colony indicate a height of 

 more than 25 mm. The zooecia are moderately large, those at the grow- 

 ing tips about 0.70 mm long by 0.45 mm wide, oriented and procumbent; 

 in older parts of the colony they are turned in all directions; distinct 

 in the younger stages. The frontal is well arched, smooth or delicately 

 granulated, with a few small areolar pores ; usually there are no suboral 



