6 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY II, 



entirely naJced; body entirely naked, except the caudal peduncle, wbich is 

 sparsely cbvered with thin, imbedded scales, and a series of rather large 

 scales along the sides, on lohicli the lateral line runs; upper jaw some- 

 what protractile; mouth rather wide, nearly terminal; a single anal 

 spine. The nabme Ammocrypta is given in allusion to the habit of hiding 

 in the sand, which is characteristic of the species of this genus and 

 Pleurolepis. 



Specific characters. — General form of Pleurolepis pellucidus, but the 

 head heavier. Depth about C in length (to base of caudal — as in all 

 cases in this paper) ; head 3f ; mouth large, the upper jaw rather 

 longest, and somewhat protractile ; cheeks and opercles entirely naked. 

 A series of rather large scales, about 65 in number, forming the lateral 

 line; a few scattering scales immediately above or below lateral line; 

 behind anal and second dorsal, the caudal peduncle is covered with 

 small, thin, imbedded scales. 



Fin rays : Dorsal X — 10. Anal I, 9. The two dorsal fins very high, 

 wide apart, about equal to each other and to the large anal. Caudal 

 fin emarginate. 



Color clear translucent, without bars or spots, the lateral line shining- 

 golden in life {Bean). Spinous dorsal fin with a large black spot on the 

 membrane anteriorly, another near the middle, and some small ones be- 

 hind; other fins with their membranes dusted with small punctulations. 



Habitat. — Notalbany River, near Tickfaw, La. Collected in Decem- 

 ber, 1876, by Dr. Tarleton H. Bean, of the Smithsonian Institution, for 

 whom the species is named. The type — about 2^ inches in length — is 

 in the United States National Museum. 



The much greater height of the dorsal and anal fins, as well as the 

 generic character of the naked body, distinguish this species from its 

 sand-diving relatives, Pleurolepis pellucidus and P. vitreus. 



3. NAKOSTOMA, Putnam, MSS., gen. nov. 



The name of Nanostoma, a manuscript genus of Darters, has been 

 current in ichthyological circles for some time, and it has once or twice 

 appeared in print, but no attempt has ever been made to characterizes 

 it. I find in the National Museum two species of Etheostomoid 

 fishes, labelled by Prof. Putnam Nanostoma, one of which seems to be 

 identical with Pcecilichthys zonalis Cope. These species cannot well be 

 referred to Pcecilichthys, as they have a complete lateral line. From 



