NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA CHEILOSTOMATA 67 



length ; cryptocyst narrow, sharply descending, delicately crenated. Opesia 

 oval, narrower at the distal end. Spines all tall, especially the distal ones, 

 usually 8 or 9 on each side but often only 5 or 6 ; also there are 2 or 3 

 smaller spines distal to the oral spines, often wanting. The avicularia 

 are minute, sessile, on the outer side of the mural rim usually a little 

 proximal to the operculum, with a short-triangular mandible. 



The ovicell is prominent, subglobose, 0.24 mm wide, and when com- 

 pletely calcified it has a pointed umbonate process just above the aperture. 

 (Hincks' figure, 4a, plate 20, is misleading as the "horn-like projection 

 from the center of the oral margin" appears to be horizontal). 



Canu and Bassler were aware of the similarity to corniculifera in 

 describing their Cauloramphus triangularis from the Pleistocene of Santa 

 Barbara, but they could not know the range of variation in corniculifera. 

 Except for the difference in size, the characters of triangularis fall within 

 the range of variation in corniculifera. It cannot be a Cauloramphus on 

 account of the hyperstomial ovicell, and the "semicircular area" is similar 

 to that of corniculifera before calcification is complete. 



Apparently this species has not been noted living since Hincks de- 

 scribed it from Cumshewa, British Columbia. 



Hancock Station 1171-40, Catalina Island, California, 38 fms, on 

 brachiopod shells. Also at Tomales Bay, California, 6 fms, on a clam 

 shell. 



Callopora cratlcula (Alder), 1857 

 Plate 6, fig. 7 



Membranipora craticula Alder, 1857 :144. 

 Membranipora craticula, Hincks, 1880:147. 

 Callopora craticula, Osburn, 1923 :8D. 



Zoarium encrusting, forming a very spiny delicate layer on shells, 

 stones, etc. Zooecia usually quite regularly disposed, 0.40 to 0.55 mm 

 long by 0.25 to 0.30 mm wide; gymnocyst well developed; cryptocyst 

 small ; mural rim raised and narrow and beset with 7 to 9 spines on each 

 side, the two anterior pairs long and erect, the others progressively shorter 

 toward the proximal end and recumbent over the opesia; opesia oval, 

 0.25 to 0.30 mm long. There is a salient avicularium, with triangular 

 mandible, on the gymnocyst in the midline or on either side; when an 

 ovicell is present the avicularian chamber is usually enlarged and partial- 

 ly covers the distal end of the ooecium and the mandible is enlarged. 

 The ooecium is large, hyperstomial, not closed by the operculum, smooth, 

 with a raised rib across the middle. 



