CR USTA CEA—OSTRA CODA . 



347 



32. H. retif era Ulrich. {¥ig.\66o,p,p'jq.) Devonic. 



Sulcus broader, hjnge line relatively shorter than in preceding; 

 posterior end the more convex. 



Bryozoa beds (Onondaga) of Falls of Ohio. 



Fig. 1660, a-Cy Cera/opsis chambersi (57), interior and exterior of right valve, X 

 12; d, Pfimitia seminulum (24), left valve, >( i8 (somevi^hat imperfect in middle) ; 

 e-g^ Primitiopsi% punctulifera (25): <?, young valve; f, g, adult left valve, X ^^ 5 ^^~J^ 

 yiichmina abnormis (27), right valve, X ^^ 5 ^i ^- nia^'ginata (28),' left valve, X 

 14; /, I\ m, Moorea bicornuta (44), right valve, X ^5 > '^j ^''j Sirepu/a plantaris 

 (45), interior and exterior of left valve, X ^^ 5 <^. ^' sigmoides (46), left valve, X i^ \ 

 p, p\ q, Halliella retifera (32), left and right valves, and basal view of latter, X ^4 '•> '''■> 

 r' , s, Clenoholbina fulcrata (61 ), right and left valve and posterior view of latter, X ^o » 

 t, t\ C. ciliata (62), exterior of left and interior of right valve, X 1% 5 ^> Hollina 

 spiculosa (82), right valve, X lO ; z', H. armata (80), right valve, yn^ \o \ w, w^^ x, 

 H. cavimarginata (81), exterior, posterior and interior of left valve, X "^^'^ y^ y^y^'t 

 H. ajitispinosa (79), three views of a left valve, X 1° 5 ^1 ^' ^ Bollia pumila (52), X 

 10. [d-gy in and n, n^ , 0, after Jones ; the rest after Ulrich.) 



XV. Dtlobella Ulrich. 



Subovate or somewhat reniform, bilobed Beyrichian shells; lobes 

 very large, subequal and almost completely separated by a deep 

 subcentral vertical or oblique sulcus. One species. Ordovicic. 



(Several species from the Lower Siluric drift of Prussia, and 

 referred to Entomis by Krause, probably belong here.) 



