Jordan and Evermann. Fishes of North America. 3157 



aa. The eye a vestige, not functional; vitreous body and lens mere vestiges, the eye col- 

 lapsed, the inner faces of the retina in contact. Maximum diameter of eye 

 about 200/ti. 



d. Xo scleral cartilages, no pigment in the pigment epithelium ; a minute vitreal 

 cavity: hyaloid menihrnne with blood vessels; pupil not closed; outer nuclear, 

 outer reticular, inner nuclear, inner reticular, gangliouic, and pigment epi- 

 thelial layers differentiated ; cones probably none ; no eye muscles. Maximum 

 diameter of eye 180,u Eye probably connected with brain throughout life. 



TYPHLICHTHYS, 322. 



dd. Scleral cartilages present; pigment in the pigment epithelium; vitreal cavity 

 obliterated, no hyaloid membrane; pupil closed; some of the eye muscles 

 developed ; no outer reticular layer ; outer and inner nuclear layers merged 

 into one. Eye in adult not connected with the brain. 



e. Pigment epithelium well developed; cones well developed; ganglionic cells 

 forming a funnel-shaped mass through the center of the eye; pigmented 

 epithelium over the front of the eye without pigment. Maximum diameter 

 of eye about 200/x. Ventral fins present. AMBLYOPSIS, 323. 



ee. Pigment epithelium developed over the distal face of the eye, rarely over the 

 sides and back; no cones ; nuclear layers mere vestiges; the ganglionic 

 layer restricted to the anterior face of the eye, just within the pigmeuted 

 epithelium. Maximum diameter of the eye about 85/. Xo ventral fins. 



TROGLICHTHYS, 322 (a). ' 



Page 744. To the synonymy of Eucalia inconstans (Kirtland), add the 

 following : 



Gaxterosteus gymnctes, DAWSOX, Canadian Naturalist, Vol. TV, Xo. 5, October, 1859, 321- 

 324, figs. 1-3, Montreal, Canada. (Coll. Prof. J. W. Dawson.) 



Page 789. Recent investigations made by Dr. Jordan in certain fresh- 

 water streams and lakes of Mexico resulted in the discovery of several new 

 species of AtherinicUv and new facts regarding other species: 



1157. ESLOPSARUM JOBDAM (Woolman). 



Locality, Rio Verde, Aguas Calientes, Mexico. 



Two specimens of Eslopsarum jordani were collected, together with 

 numerous individuals of E. arge. Chirostoma breve, Steindachner, is probably 

 identical with E. jordani, as already supposed by us. 



An examination of a number of species of Eslopsarnm and of Chirostoma 

 shows that the number of vertebra?, in addition to the character of the 

 scales, furnishes a distinguishing generic feature. 



Species. 



Vertebrae. 



Eslopsarum jordani 

 arge 



Chirostoma humbolfitlanum 



chapalce ; 



promelas 



diazi I 



crystallinuin I 



ocotlane 



Chirostoma contains two very marked types of species. The one repre- 

 sented by the typical species, Chiroatoma humboldtiaHt<m,\iiLS the flesh firm 



