175 



Found at "West 

 H a 111 b 11 r g , E v i e 

 County." (Hall.) 

 Found also in the 

 Stictopora and De- 

 niissa beds, at Sec- 

 tion o, Eig,hteen Mile 

 Creek (rare). 



%^l 



i 



f^gs^ 





w 



■'- »^*i^ 0i<f' c-' ''^>''' 



Fig. 71. Tmniopotri exiyua. Natural size, and 

 portion enlarged, x fi (after Hall and Simpson). 



Genus A(^R0GENIA. Hall. 



[Ety. : A/i-i't/.s. sharp; (jcncd, growth.] 



(ISSl; Trans. Albany Inst., Vol. X., p. 193.) 



'"Zoariuin" (Bryozouni) ''ramose, proliferous; eonsisting 

 of flattened branches, two 

 proceeding- from the truncate 

 termination of the previous ^^ 

 one, and continuing growth in 

 the same manner. Branches 

 striated below, flattened and 

 celliiliferous aliove. Inter- 

 cellular structure vesiculose. 

 Apertures ai-ranged in longi- 

 tudinal rows." (Hall, Pal. 

 M. Y., Vol. VI.,p. XX.) 



A C R O (J K X I A PK O L T F E K A. 



Hall. (Fig. 7l>.) (Pal. N. Y., 

 Vol. YI..]). 2()7, PI. LXni.) 



DLstinguishini>- ( luirncters. — 

 Peculiar growth and jointage; 

 small circular apertures; weak 

 peristomes ; prominent liina- 

 ria ; continucjus ridges separat- 

 ing apertures. 



Found in the " Hamilton group, P^ighteen Mile Creek, Erie 

 County, N. Y." ( Hall, explanation of plates.) 



Fig. 'i'Z. Acrocieiu'a jvolifera. Natural 

 size, and a portion enlarged, x ti (after Hall 

 and Simpson). 



