26 Hill — P(dcoufolo(ji/ of tJic Triiiify Divmon. 



This is one of the most characteristic species of the very base 

 of the Glen Rose beds in Parker, Hood, and Comanche counties, 

 and is the form which the writer once inferred to be analagous 

 to Ambnnicardia coohil Wliitfield,* from the Raritan chi^^s of 

 New Jersey, which the fragments then found strongly resem- 

 bled in outline and marking. The discovery of the specimen 

 here figured, however, for the first time affords evidence for their 

 satisfactory generic identification. 



The specimen figured was found al)Out three miles east of 

 Millsap, Texas, at the contact of the Trinity sands and the cal- 

 careous Glen Rose beds. I liave also found the species near 

 S})ringtown, Parker county, and at Comanche, in the same liori- 

 zon. 



Cucullaea terminalis Conrad. 



(See Report United States and Mexican P)Oundary Surve}'' 

 Washington, 1857, vol. i, p. 148, plate iv, figs, 'la and h.) 



Casts of this species are frequently met with in tlic Glen Rose 

 beds. The shell has not yet been found. 



Barbatia parva-missouiiensis Hill. 



This species, from Pike county, Arkansas, was described and 

 figured in my Arkansas Report, p. 133, plate iv, figs. 4r/, 4/>, 5, 

 and probably fig. 22, of plate ii, of same report. . 



Tiigonia stolleyi sp. nov. 



Plate III, Figs. 3 and 5. 



Semi-lunate in general outline, V)caks well forward and strongly 

 recurved ; anterior and pallial n)argin a strong continuous curve ; 

 posterior portion elongated with truncated ])osterior margin ; 

 cardinal area compressed. Surface marked l)y flexuous, noduled 

 costa", about twenty -two in number, narrow and high, separated 

 by lu'oad intercostal areas as in 2'. a/;^/br»i?.s Lmk. ; depressed 

 cardinal area bordered on its outer side by a long narrow groove 

 and marked by cross-ribs, flexing anteriorly. 



This Triffonia diff'ers from T. cmoryi Conrad, of the Washita* 

 Division, in its general outline and entirely distinct surface mark- 



*See Report of Arkansas State Geolouical Survey for ISSS, vol. ii, p- 

 120. 



