Jordan and Evermann. — Fishes of JVori/i America. 1083 



profile of head rounded, no angle above orbits, the short snout with rounded 

 profile, but not obtuse. Preniaxillaries on level of pupil, nonprotractile. 

 Prcorbital extremely narrow, little wider than the broad end of the max- 

 illary bone, which is not concealed by it. Gill membranes rather narrowly 

 united across the isthmus, their width anteroposteriorly \ diameter of 

 eye. Opercular spine bifid, with 2 minute free points. Preopercle entire. 

 Eye large, 4 in head to end of opercular spine. Interorbital space wide, 

 strongly convex, its width equaling length of snout, ')\ in head. Fins all 

 small ; distance from front of dorsal to tip of snout \ length ; dorsals low, 

 the 2 joined at base, the last spine appearing longer than the preceding 

 one and belonging to the second dorsal ; longest dorsal spine \ head ; 

 length of last dorsal spine t diameter of orbit, the spine erect and con- 

 nected for its entire height with the following soft ray ; the next to the 

 last spine directed very obliquely backward, and appearing much shorter 

 than the last spine, its membrane joiuiug last spine at base only ; base of 

 spinous dorsal as long as head in front of preopercular margin, its highest 

 ray half head ; anal fin very small, the spines large and strong, first spine 

 much longer and stronger than the second, 31 in head, equaling length of 

 snout and half eye ; highest soft ray of anal equaling length of snout and 

 eye ; pectorals and ventrals both very small ; the pectoral short, broad, 

 and rounded, reaching the same vertical as ventrals, \\ in head, and having 

 but 11 rays; ventrals close together, 1^ in head. Sides of head, breast, 

 and nape wholly naked ; body with rather large, ctenoid scales, uniformly 

 covering bellj^; lateral line straight, incomplete, reaching to below mid- 

 dle of soft dorsal. Color in spirits : Light olive, sides and above obscurely 

 tesselated with darker ; nine short dark cross bars on back, and traces ol 

 about an equal number on middle of sides, those on front of sides faint, 

 only the last 5 evident ; a black humeral spot present ; a faint dark streak 

 downward and 1 forward from ej^e, and a small dark spot above and 

 behind orbit ; cheeks dusky ; top of head vermiculated with dusky brown- 

 ish ; spinous dorsal with a basal series of small blackish spots, each in the 

 midst of H translucent area, the terminal portion of membrane rendered 

 dusky by minute close-set dark points; soft dorsal and caudal barred 

 with light and dark lines; pectorals and ventrals translucent, unmarked. 

 Length If inches. Streams of Chihuahua, Mexico ; an aberrant species 

 of darter, looking like a young bass. (Named for .John Potts of Ciiihua- 

 hua, its discoverer and an "esteemed friend" of Dr. Girard.) 



Aplesion potlsii (missprinted potsU), Girard, Proc. Ac. Kat. Sci. Phila., 1859, 102, tributaries of 

 Chihuahua River. (Coll. John Potts.) 



Elheostoma micrnpleriis, Gilbert, Proc. U. S. Nat. Mus., 1888, 289, Chihuahua, Mexico; Ever- 

 mann & Kendall, Bull U. S. Fish Comin., xii, 1892 (1894), llo, pi. 35. 



Bolsosiima pofisii, Vaillant, Recherches, 94, 1873. 



Elheostoma pottsii, Boulenger, Cat., i, 74. 



Subgenus OLIGOCEPHALUS, Girard. 

 1473. ETHEOSTOMA lOW.E, Jordan & Mef k. 



Head 3* to 4; depth 4 to 51; eye 4 to 5 in head. D. VII to X-10 or 

 11 ; A. II, () to 8 ; scales .o-55 to 63-11, pores 20 to 34. Body rather more 

 elongate than in Elheostoma jessice ; the caudal peduncle rather long and 



