REPORT ON THE HEXACTINI^ 17 



Leiotealia, Hertwig. 



Isotealia, Carlgren — possibly a synonym of Leiotealia. 

 Epiactis, Verrill. 



Gyractis, Boveri — possibly a synonym of Cribrina. 

 Ixalactis, Haddon. 



Pseudophellia, Verrill — possibly a synonym of Tealiopsis. 

 ? Tealiopsis, Danielssen. 

 ? Thelactis, Klunzinger. 

 ? Physactis, Verrill. 



Representatives of the first three of these genera occur in the 

 collection. 



Genus Cribrina Ehr. 



Cribrinidae without true acrorhagi ; usually with numerous 

 perfect mesenteries which are in some cases arranged on other 

 than a hexamerous plan ; sphincter strong ; ectodermal muscu- 

 lature of the disk and tentacles not imbedded in the mesogloea'; 

 column wall destitute of an epidermal covering and provided 

 with verrucEE arranged more or less distinctly in vertical rows ; 

 tentacles simple. 



Rather too much attention has been devoted in the past to 

 the arrangement of the verrucae, in members of the Cribrinidae, 

 whether they were arranged distinctly in vertical rows or not 

 and whether these rows extended all the way down the column 

 or only part of the way down. I plead guilty to such a misunder- 

 standing of the value of the verrucae in an earlier paper ('89) in 

 which, basing my identification on this feature I described as an 

 Aulactinia (^A. stelloides) a form which is really a Cribrina and as 

 a Bunodes (B. tceniatiis) a form which is really an Anthopleura 

 (^A. granitlifevci). 



It seems now that the presence of verrucae, without regard to 

 their arrangement, is sufficient for the genus, distinguishing it at 

 once from Leiotealia, Epiactis and Isotealia. The absence of true 

 acrorhagi, characterized by a marked development of nemato- 

 cysts, distinguish it from Anthopleura, while the ectodermal situ- 

 ation of the longitudinal muscles of the tentacles and of the radial 

 muscles of the disc may serve as a distinction from Urticina. 

 Annals N. Y. Acad. Sci., XIV, June 5, igoi — 2. 



