NO. 3 OSBURN : EASTERN PACIFIC BRYOZOA CYCLOSTOMATA 641 



the middle of the ooecial swelling. There are several types of ooecio- 

 stomes, which may eventually result in the separation of the genus as 

 suggested by Canu and Bassler (1920:740). (1) In some species the 

 ooeciostome is not associated with a tubule but is quite independent among 

 them; (2) in others it is a high tube at the side of a peristome and 

 more or less connate with it; and (3) in still others it is a transverse 

 or arcuate pore at the base of a peristome and without an ooeciostome. 



Pustulopora intricaria Busk, 1875:22, which is the genotype, is an 

 erect, branching species with the ooeciostome isolated and situated a 

 little proximal to the middle of the long ovicell, which surrounds a large 

 number of peristomes. 



In my opinion Canu and Bassler have depended too much on a single 

 character, that of the ovicells surrounding peristomes, for this character 

 appears not infrequently to a lesser extent among other genera, even 

 in species of genera that do not ordinarily show it, such as Tubulipora, 

 Plagioecia, Fasciculipora, Frondipora, etc. Even in Plagioecia patina, 

 the genotype of that genus, a peristome may occasionally be surrounded. 

 It is also true that in Diplosolen and Crisulipora, which usually have a 

 number of included peristomes, ovicells occasionally occur which have 

 failed to surround any peristomes. 



The erect species of our eastern Pacific members of this genus agree 

 in having an elongate ovicell which extends much beyond the isolated 

 and more or less centrally placed ooeciostome. Others, such as those 

 described from the Galapagos Islands by Canu and Bassler, D. striatula, 

 D. subpapyracea and D. meandrina, with transversely broad ovicells and 

 terminal, median ooeciostomes, more properly belong under Plagioecia 

 notwithstanding the inclusion of some peristomes. 



It would appear to be true of any species that when the ovicell con- 

 tinues to grow forward around a distal peristome, the walls may come 

 together and coalesce to enclose it. However this may be, there is cer- 

 tainly a group, Diaperoecia, with a well-defined facies which shows an 

 extended ovicell enclosing numerous peristomes and with a non-terminal 

 ooeciostome. 



The species of the present list show two distinctly different types of 

 ooeciostome; in D. intermedia, johnstoni and claviformis the ooeciostome 

 is a narrow tube at the side of a peristome and is proximal in position, 

 while in califoniica and floridana the tube is wider, broadly flared at 

 the tip, entirely free from the peristomes and situated more medially. 



