NO. 1 OSBURN: eastern pacific BRYOZOA CHEILOSTOMATA 85 



line, and resembling those of D. spathulifera except that they are more 

 elevated. The ovicell is prominent, globular, 0.18 to 0.20 mm in breadth, 

 and its surface is reticulated like the gymnocyst. Pore chambers are 

 present, as in D. spathulifera. 



O'Donoghue described the species in the genus Membranipora and 

 later removed it to Amphiblestrum. It cannot, however, be associated 

 with that genus as the calcified frontal enclosure is a gymnocyst and there 

 is no evidence of an expanded cryptocyst. Aside from the spines its es- 

 sential characters are those of D. spathulifera. 



It was recorded by O'Donoghue from numerous localities in British 

 Columbia, from Victoria northward. 



A specimen in the Hancock collections is from Cadboro Bay, Victoria, 

 British Columbia. 



Genus RETEVIRGULA Brown, 1948 



Retevirgula Brown, 1948:109. 



This genus has been recently established to include those membrani- 

 porine species which are similar to Callopora, but in which the zooecia 

 are more or less dissociated and united by tubular connecting processes; 

 which have mural spines ; rounded vicarious avicularia on zooeciules oc- 

 cupying a place in the zooecial series ; a hyperstomial ovicell with a frontal 

 fenestra, and which are without dietellae. The genotype is Membranipora 

 acuta Hincks, 1885:249. 



The species have hitherto been distributed by various authors in 

 Membranipora, Beana, Pyrulella, Mystriopora (?), Hincksina and 

 Cauloramphus. The genus seems to have a closer relation to Pyrulella 

 than to any other but the species of that genus have frontal avicularia 

 and are without connecting tubules. 



Key to Species of Retevirgula 



1. Zooecia large and broad, opesia oval, interzooecial fenestrae and 



zooeciules rather rare lata 



Zooecia smaller and narrower, opesia elliptical, fenestrae and 



zooeciules frequent 2 



2. Zooecia always disjunct and connected by tubules, with con- 



spicuous fenestrae; the proximal 4 pairs of spines curved 



over the opesia tubulata 



Zooecia disjunct or in contact ; proximal spines long, not curved, 



but lean somewhat over the opesia areolata 



