THE MOUNT DESERT REGION 297 



Oncoiisoeciiclae Canii, 1918 

 ' ' Stomatopora diastoporides ' ' 



Various species have been confused under the name diasto- 

 porides on the American side of the Atlantic as they have on 

 the European side. This is due to the fact that older workers 

 paid little attention to the ooceia and attempted to draw their 

 descriptions from the zoaria. In more recent years, we have 

 learned that the zoarial form may vary widely in this group 

 and the only certain criteria are those of the ovicell and its 

 aperture, the ooeciostome. This, in fact, holds good for 

 most of the Cyclostomata. 



At least three northern species on the American coast are 

 included under the name diastoporides in former reports of 

 those who have worked on Canadian and New England Bryo- 

 zoa, and are here separated on the basis of the ooecia, which 

 are so striking as to leave no doubt of their distinctness. 

 After having determined the species on ooecial characters, it 

 is possible to note certain zoarial and zooecial characters by 

 which they may be separated without much doubt when oeecia 

 are lacking. 



Since it appeared necessary, in order to straighten out the 

 tangle, to compare the American species with type and other 

 named material from European waters, specimens were sent 

 to Dr. Anna B. Hastings, of the British Museum of Zoology, 

 who kindly undertook the work of comparison and made an 

 exhaustive report (in litt.). I desire to express my thanks 

 for this work, without which the following analysis of these 

 species would have been impossible. 



Oncousoecia diastoporides (Norman), 1868. PL 2, figs. 

 5-8. (Alecto. Stomatopora, and Diastopora diastoporides 

 auctt. ; Osburn, 1912, p. 218, Stomatopora.) The only posi- 

 tive previous record for the eastern coast of North America 

 is the one above, by Osburn, for more by accident than 

 otherwise the species from Woods Hole, Mass., was correctly 

 identified. Specimens preserved in the author's collection 

 have been carefullv restudied, and some of them referred to 



