102 Hill The Invertebrate Fossils of the 



Nerinea subula Roemer. 



Glauconia (?). 



Cerithium obliterate- granosum Roemer. 



Cerithium austinensis Roemer. 



Trochus texanus Roemer. 



Solarium planorbis Roemer. 



Natica (Amauropsis) avellana Roemer. 



Requienia patagiata Ch. A. White. 



Monopleura marcida Ch. A. White. 



Monopleura pinguiscula Ch. A. White. 



Lucina acute-lineolata .Roemer. 



Requienia patagiata Ch. A. White. 



The following forms have a more general occurrence : 



Ostrea munsoni sp. nov. 

 Radiolites texana Roemer. 



davidsoni sp. nov. 

 Requienia texana Roemer. 

 Ichthyosarcolithes anguis Roemer. 

 Monopleura marcida Ch. A. White. 

 Ammonites (Buchiceras) pedernalis von Buch. 



(Schloenbachia') acute- car mat us von Buch. 



In addition to the foregoing numerous species have been 

 described under the generic name of Caprina, owing to the occur- 

 rence in immense quantities of a fossil supposed to have belonged 

 to that genus. These fossils, however, are usually imperfectly 

 preserved, but it can now be said with assurance that none of 

 them belong to that genus, but are mostly Ichthyosarcolithes or 

 Radiolites. All of the so-called Caprinas heretofore described 

 from Texas come from this horizon. 



Most of the Austin species occur in the bluffs of the south 

 bank of the Colorado and Barton creek, just west of Austin, as 

 beautifully preserved calcite pseud omorphs. Usually the lime- 

 stone is very barren of all fossils except the Rudistes and Ghamidx. 



Other aberrant Chamidw and Rudistes from the Texas Creta- 

 ceous have long been known, but their exact stratigraphic range 

 has not been clearly stated. With the exception of Radiolites 

 davidsoni herein described, the stratigraphic occurrence of all the 

 species was unknown to their authors when they described them. 

 Many were described from imperfect . specimens, and all the 

 writers previous to Dr. White's valuable contribution expressed 



