234 NOETH AMERICAN FAUNA. [No. 7. 



This genus seems most nearly allied to Orestias, of which numerous 

 species have been described from lakes in the high Andes of South 

 America. 



Empetrichthys merriami, sp. hot. (Plate v.) 



Type locality. — Ash Meadows, Aimrgosa Desert, on boundary between California 

 and Nevada. 



In form and general appearance much resembling the mud minnow 

 ( Umbra limi)\ though somewhat deeper and more compressed. 



Head compressed, its upper surface slightly convex. Mouth very 

 oblique, with a distinct lateral cleft, the maxillary free at tip only, reach- 

 ing slightly behind front of eye. Length of gape (measured from tip of 

 snout to end of maxillary), 3 J in head; interorbital width, 2% ; length of 

 snout (from front of orbit to middle of upper jaw), 3f. Eye small, its 

 greatest oblique diameter 5 to 5J in head. 



Distance from front of dorsal to middle of base of tail equals one-half 

 its distance from tip of snout. The dorsal begins slightly in advance 

 of anal, and ends above its' posterior third. Its greatest height equals 

 length of snout and eye. 



Caudal truncate when spread. Pectorals broadly rounded, reaching 

 halfway to vent. D., 11 or 12 (13 in one specimen); A., 14 (from 13 to 

 15). Lat. 1., 30 or 31, counted to base of caudal rays; 33 or 34 in all. 



In spirits the color is dark brown above, sides and below lighter, 

 often irregularly blotched with brown and white. The belly often 

 appears checkered, .having centers of scales brown and margins white, 

 or the reverse. Fins all dusky, the basal portions of dorsal and caudal 

 with elongated brown spots on the interradial membranes. 



Several specimens were secured at Ash Meadows and in Pakrump 

 Valley, Nevada. 



Gasterosteus williamsoni Girard. 



Type locality. — Williamson Eass, California. 



Four specimens of this species collected by Dr. A. K. Fisher at San 

 Bernardino, California, seem to differ from G. microcephalics only in the 

 entire absence of plates on the sides. In microcephalics the plates vary 

 from 3 to 7 in number, but no' specimens wholly without plates have 

 been reported from the more northern parts of its range. It is probable 

 that williamsoni will prove a southern subspecies of this widely dis- 

 tributed form, in which case the plated specimens must bear the name 

 Gasterosteus williamsoni microcephalics . The naked form has been 

 reported heretofore from San Bernardino (by Miss Eosa Smith), and 

 from Williamson's Pass by the original describer. The locality of the 

 pass I have not been able to make out. 



