BRYOZOA—CRYPTOSTOMATA. 



H3 



87. F. emaciata Hall. (Fig. 199.) Mid-Devonic. 

 Large funnel-shaped ; dissepiments thin and oblique ; keel prom- 

 inent ; apertures closely and regularly disposed. 



Hamilton of New York. 



88. F. cestriensis Ulrich. (Fig. 201, c.) Mississippian. 

 Branches irregularly dividing, slightly flexuose ; carina angu- 

 lar; apertures circular, with peristomes; reverse side rounded, 

 smooth exept for scattered nodes. 



Chester of Mississippi Valley, Kentucky, etc. 



e 



a' 



P'lG. 199. Fenestella emaciata. a, fragment of frond (reduced) ; b, non-cellulifer- 

 ous face showing striated branches and oblique dissepiments, X 4 5 ^ celluliferous face, 

 X 4 ; d, transverse section of branches, X 4 ; <?» lateral view of branches, showing 

 position of apertures, X 4- (After Hall. ) 



89. F. tenax Ulrich. (Fig. 201, b.) Mississippian. 

 Fenestrules narrower than branches ; dissepiments moderately 



thick ; no nodes, but faint striations on reverse side ; apertures cir- 

 cular, with peristomes. 



Chester of Mississippi Valley and Kentucky; Waverly of Ohio. 



LI. Semicoscinium Prout. 

 Funnel-shaped, all openings on outer side, wide, short dissepi- 

 ments, the branches appearing to anastomose on non-poriferous 

 face, whose fenestrules are subrhomboidal or rounded ; apertures in 

 two rows; median keel very high, expanded at the summit. 

 Sil.-Dev. 



90. S. tenuiceps (Hall). (Fig. 200.) Siluric. 

 Carina sharp and thin ; transverse dissepiments do not extend 



as high as the branches, sometimes scarcely visible; apertures 



