NATURAL SCIENCES OP PHILADELPHIA. 2G3 



NOTICE OF A COLLECTION OF CRETACEOUS FOSSILS FROM CHIHUAHUA, 



MEXICO. 



BY WILLIAM M. GABB. 



A small collection of Cretaceous fossils has recently been sub- 

 mitted to me for examination by my friend, Dr. J. P. Kimball, 

 who collected tbem near the centre of the State of Chihuahua, at 

 a place called Nugal, in the midst of a silver mining region. In 

 fact, the doctor represents the argentiferous veins as lying in the 

 cretaceous limestone. 1 



The fossils are of the more intei'est, since they are another link 

 in the chain of evidence, to prove an extension of the cretaceous 

 sea completely across Northern Mexico. 2 They are of the same 

 group, from which I have already described one series, collected 

 by my old friend and colleague, Aug. Remond, at Arivechi in 

 Sonora ; and the two localities are only separated by the crest of 

 the Sierra Madre, which probably showed its summits as a string 

 of islands in the ancient ocean. 



Collected incidentally during a journey made for an entirely 

 different purpose, and in a region infested by Apaches, it is not 

 strange that the series is meagre. Fortunately, it is full enough 

 to give us an undoubted key to the exact member of the forma- 

 tion. 



The following is a list of the species identified. In addition to 

 these, there is a favositiform coral, and one or two other forms 

 too imperfect for recognition. 



Hippurites Texanus, Roem. 

 Ostrea bella, Conrad. 

 Exogyra costata, Say. 

 E. arietina, Roem. 

 Neithea Texana, Roem. sp. 

 N. occidentalis, Conrad. 

 Lima Wacoensis, Roem. 

 L. Kimballi, Gabb, n. s. 

 Inoceramus, two species, indet. 



1 See Silliman's Journal, Nov. 1869, p. 378. 



2 Palaeontology of California, vol. ii. p. 257 et seq, 



