NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA CHEILOSTOMATA 99 



to 4 small distal spines ; a pair of strong cardelles ; the pericyst forms a 

 thick, low wall around the peristome but without fusing with it. The 

 operculum is well chitinized, with a narrow border and a pair of heavier 

 sclerites which extend forward from the cardelles within the lateral 

 borders and meet at some distance back of the distal border. The opercul- 

 um is connected with the frontal membrane, but is detachable. 



The large elongate avicularia are so regularly disposed between the 

 zooecia that they appear to alternate with them in series, but they are 

 interzooecial only in arrangement and not vicarious, as shown by their 

 manner of budding and by the fact that the avicularian chamber does 

 not descend below the level of the primary layer of the pericyst. The 

 mandible is elongate and narrowly spatulate, its tip much decurved with 

 its point usually fitting into the central depression; a triangular lucida 

 in its base, and hinged to strong cardelles which occasionally meet to 

 form a bar; the mandible measures 0.35 to 0.50 mm long by 0.13 to 0.16 

 mm wide at the base. 



The ovicell is rounded, about 0.25 to 0.30 mm wide ; at first promi- 

 nent, but later becoming immersed, the surface roughly reticulate ; closed 

 by the operculum. 



There is close agreement between the typical granulata Canu and 

 Bassler, 1928:45, from the Florida Straits, and the present variety in all 

 points, except in the avicularia which are broader, the sides parallel to 

 near the tip which is suddenly rounded at the hooked beak. 



Type, AHF no. 26. 



Type locality, Hancock Station 136-34, Clarion Island, 18°20'05"N, 

 114°44'40"W, 32 fms. Also at Station 137-34, Clarion Island, and 539 

 -36, Angeles Bay, Lower California, 20 fms. 



Division III COILOSTEGA Levinsen, 1909 



In this group the horizontal lamina of the cryptocyst is highly de- 

 veloped, in some cases even extending forward around the aperture, and 

 above this lies the frontal membrane. The lateral muscles which operate 

 the membrane pass downward to the dorsal wall distally to the lamina, 

 or through notches at the sides, or through special foramina at either 

 side known as the opesiules. When the opesiules are well developed the 

 distal end of the polypide is more or less enclosed in a calcified polypide 

 tube. Avicularia or vibracula are usually present and always interzooecial. 

 Ooecia may be either hyperstomial or endozooecial. 



