SUB-OHM.K II 



TREPOSTOMATA 



277 



Family 0. Batostomellidae. Ulrich. 



ramose, occasionally sub-lolate, massive, laminar, or parasitic, often 

 consisting of superimposed layers. Zocecia with thick uv///.< in H" ///"'/ rtffion, </.</><///// 



,!,,/ nrinii here as fn*<l. 



those in pei'ij>li>i'nl 



central perforation. 



1 1 til/ IIUKII- 



/nirr.< n.<ii<iHii fin* at ; tin- 

 Intt.r tin, ill, './'/.// ////./- 



-initt'iit. Ordovician to 

 Permian. 



Bythopora, Miller 

 ami Dyer. Small 

 branching stems. Aper- 



Fio. 463. 



Ulr. Chester Group; Kentucky. A, B, Vertical 

 sections, one with and the other without diaphragms, u/i. C, Tangential 





tures oblique attenuate se< -'t' u ". 14 /i- />, Surface, 14 /i. On either side of C are branches of the natural 



above. Interspaces 



canaliculate, with an occasional mesopore or none. Ordovician. 



Callotrypa, Hall ; Silurian. Eridotrypa, Ulrich ; Ordovician to Devonian. 



A TJ Batostomella, Ulrich (Geinit- 



zella, W. and W. ; Trematella, 

 Hall), (Fig. 463). Slender 

 branches, without monticules. 

 Apertures small, circular, or oval. 

 Interspaces rounded or canal- 

 iculate, spinulose, the acantho- 

 pores small and usually very 

 numerous. Mesopores small, 

 sub-circular. Diaphragms few. 

 Devonian to Permian. 



Stenopora, Lonsd. (Fig. 464). 

 Zoaria ramose, sub-lobate, massi ve, 

 laminar, or parasitic. Surface 

 Zocecial walls periodically thickened in the mature region. 



Fio. 464. 



>y. //c/xi;-,; mill rii-inut, Ulr. Keokuk Group; Illinois. Vertical 

 (X)and tangential (/.') sections showing nioniliform walls and per- 

 forated diaphragms, i*/i (after Ulrich). 



even or montiferous. 

 Large acanthopores at many 

 of the angles between the 

 zooecia. Mesopores never 

 very numerous, irregularly 

 distributed. Diaphragms 

 sometimes very scarce, but 

 in most American species 

 abundant in the peri ]>li era 1 

 region, and with a large 

 central perforation. Sub- 

 Carboniferous to Coal 

 Measures. 



Anitotrypa, Ulrich. 

 Divisional line between ad- 

 joining tubes more sharply 



defined, and periodic swellings of the walls much less distinct than in Stenopora. Acan- 

 thopores and mesopores absent ; perforated diaphragms numerous. Sub-Carboniferous. 



? Lioclema, Ulrich (Fig. 465). Ordovician to Sub-Carboniferous. 



Fio. 465. 



Liockma foliata, Ulr. Keokuk Group; Illinois. A, Vertical section, 

 .ngential section, '^/i- C, Portion of wall and acanthopore, ^/i 



