1890.] NATURAL SCIENCES OF PHILADELPHIA. 451 



Trigonia Mooreana, Gabb. — Cretaceous of Texas. 

 (^Trigonid cremilata, Roemer). 



Remondia f areata, Gabb. 



Gryphea mucronata, Gabb. 



Exngyra plicata, Lam. — Cretaceous of Texas. 



Ostrea sp. indet. 



Pyrina Parryi, Hall. — Cretaceous of Texas. 



Cyphosoma Texanitni, Roemer. — Cretaceous of Texas. 



Tarbinolia !' Texana, Conrad. — Cretaceous of Texas. 



There can be no question, it appears to me, that these fossils re- 

 present, as Gabb also supposed, a part of the Upper Cretaceous 

 formation, synchronous with at least some of the deposits described 

 by Roemer from Texas (Senonian or Turonian). Most of the species 

 are beautifully, or, perhaps more properly, artistically, figured in 

 Gabb's report, but in many cases the artistic effort renders determina- 

 tion from them all but impossible. Having had the type-series 

 under my eye among the collections of the Academy of Natural 

 Sciences I venture to subjoin the following notes on species, in antic- 

 ipation of a more extended report which it is my intention to 

 prepare at a future day. 

 Ammonites Pedernalis, Von Bueh. 



I am not sure that the form here described is really Von Buch's 

 species. Gabb calls attention to the flattened dorsum in distinction 

 to the sharp back of the typical A. Pedernalis, but remarks that he 

 has observed variation in this respect. But whether the form or 

 not, it certainly represents the group which Von Buch has designated 

 " Cretaceous Ceratitic xVmmonites."^ In Gabb's figure (PI. 35, fig. 1, 

 la) the folds on the surface are much too numerous and regular; 

 not more than one-half the number appear in the single type-spec- 

 imen, and they are more in the nature of " swellings " than true 

 plications. A portion of the inner whorl that is exposed is entirely 

 destitute of these folds, and shows the ceratitic markings very 

 clearly. 



1 Ueber Ceratiten — Von Buch's Gesammelte Schriften, II, p. 871, Berlin, 

 1885. The species is referred by Neumayr and Uhlig to the group Engonoceras 

 (Ueber Ammonitiden aus den Hilsbildungen Norddeutschlands, Palreontographica, 

 1881, p. 138), while by Douville, wlio more accurately represents the sutural con- 

 figuration, it is placed in Sphenodisciis i Classification des Ceratiiesde la Craie, Bull. 

 Soc. Gecl. de France, ]8!)U, pp. 288-89.) 



