BRYOZOA. 457 



The specific name is given in honor of Rev. I. F. Stidham, to 

 whose generosity I am indebted for the type specimens. 

 Position and locality: Cincinnati group, Brown Co., Ohio. 



LEPTOTRYPA KEMIPILARIS Ulrich. 



PI. XXXVI, Fig. 5-5d. 



Zoarium small, massive, bat varying in shape from lenticular 

 to subglobose; usually hemispherical. Surface smooth or with 

 low broad elevations having a cluster of larger cells at their 

 apices. Zooecial tubes direct, thin-walled throughout, with sub- 

 polygonal apertures, about eight in two mm. Diaphragms 

 usually wanting, occasionally a few developed as the tubes 

 approach the surface. Acanthopores of moderate size and num- 

 ber, situated at the angles of the zocecia. 



The greater regularity and slightly larger size of the zooecia, 

 the different shape of the zoarium, and the almost total absence 

 of diaphragms distinguish this species from L. stidhami, its 

 nearest congener. 



Position and locality: Cincinnati group, Covington, Ky., about 

 300 feet above the bed of the Ohio river. 



DIPLOTRYPA Nicholson, 1879. 



(Pal. Tab. Corals, p. 292.) 

 (For generic diagnosis see page 378.) 



In the general aspect and composition of the zoarium this 

 genus presents much resemblance to Prasopora Xich. and Ethr. 

 Juii. The absence of true cystiphragms, however, is an impor- 

 tant and easily recognized peculiar-it}-, that not only distin- 

 guishes the two genera, but also casts much doubt upon the 

 family relations of Diplotrypa. Such species as D. H hiteavsi Nich., 

 and D. milleri Ulr., point to decided affinity with the CALLO- 

 PORiD-E. On the other hand D. regularis Foord, D. infida and D. 

 jjtitella Ulr., approach more nearly to Prasopora. In this 

 group of species the zooecial tubes are crossed by oblique, more 

 or less recurved, or occasionally even overlapping diaphragms. 

 In the last instance they simulate isolated cystiphragms in a 

 marked degree, but a careful examination has failed to show 

 that they are anything else than irregular or modified dia- 

 -57 



