R. T. Hill — Texas Section of American Cretaceous. 303 



O. Marshii Marcou. 



0. subovata Slmra. 

 Gryphcea sinuata, var. ameri- 

 cana Marcou. 



Exogyra Valkeri White. 

 Gryphcea Pitcheri Mort. 

 var. navia Con. 

 var. fornicidata White 

 var. dilatata Marcou. 

 Lima wacoensis Roem. 



L. leonensis Roem. 



L. Kimballi Gabb. 

 Neithea occidentalis Con. 



Pecten quadricostatus Roem. 



P. duplico status Roem. 

 Neithea cometa D'Orb. 

 f N Wrightii Shum. 

 Janira fleuriausiana D'Orb .* 

 Lucina, sp. hid. 

 Triyonia, sp. incl. 

 Cardium hillanum Sowb. 

 Astarte texana Con. 

 Slear?\sa ? robinsi White 

 Grassatella lineata Shum. 

 Gervillopsis (" Dalliaconcha ") 



invaginata White. 

 Panopma subparallela Shum. 

 Panopaia texana Shum. 

 Pachyma austinensis Shum. 

 Pachyma ? compacta White. 

 Pinna, sp. incl. 

 Inoceramus, sp. ind. 

 Gaprina crassifibra Roem. 



Gaprina guadalupm Roem. 

 Gaprina occidentalis Con. 

 Gaprina planata Con. 

 Gaprina quadrata Con. 

 Gaprina texana Roem. 

 Requienia texana Roem.f 



R. bicornis Meek. 



R. patigiata White. 



R. Romeri Gabb. 

 Hippurites texanus Roemer. 

 Natica? (Tylostomaf) praz- 



grandis Roem. 

 Nerinea, sp. ind. 

 Pleurotomaria austi n e n sis 



Shum. 

 Tarritella marnochii White. 

 Cinidia, sp. no v. 

 Apporhais, sp. nov. 

 Nautilus neocomensis D'Orb. 

 Samites Fremonti Marcou. 

 Ancyloceras, sp. nov. 

 Turrillites brazosense Roem. 

 Ammonites acutocarinatus 



Roem., Shum. 

 Ammonites Belknapi Marcou. 

 A. brazosensis Shum. 

 Ammonites geniculatus Lea. 

 Ammonites leonensis Con. 

 Ammonites Shumardi Marcou. 

 Ammonites Swallovi, Shum. 

 Ammonites vespertinus Mort. 

 A. texanus? Roem. 



The Fredericksburg Division. 



The provisional line of geologic demarcation between the 

 two divisions is the Caprina limestone of Shumard. This is the 

 horizon of greatest resistance in the Comanche series. It con- 

 sists of more massive and firmer semi-crystalline limestones 

 than those above and below it, and does not yield so readily to 

 denudation, so that it is preserved in many places as the cap- 

 rock of extensive mesas and buttes. Wherever it is preserved 

 there will be found below it the strata which have been suffi- 

 ciently described by Roemer from near Fredericksburg, con- 

 sisting of softer crumbling, gritty limestones and lime marls. 

 These strata were also well described by Shumard as the 



* I have found this form at Austin, and see no reason for making it a new 

 species. 

 f Probably identical with Gaprotina lonsdalli D'Orb. 



