Jordan and Evermann. Fishes of North America. 2785 



area between eyes triangular, with a median groove extending from fon- 

 tanel forward to tip of snout, its posterior end a little behind eye, the 

 granulations on each side of it extending forward as far as posterior bor- 

 der of pupil ; opercles with no radiating stri;e. Gill membranes forming 

 a very narrow fold across the isthmus. Gill rakers 5 -f- 12. Nostrils 2 on 

 either side, large, placed close together and near tip of snout, the poste- 

 rior with a large flap; axillary pore well developed; humeral process 

 smooth, very short, 4 to 5 in pectoral spine. Base of dorsal 2f to 2^- in 

 head ; dorsal spine long and very strong, If to 1^ in head, its upper ante- 

 rior seme small and tubercle-like, its upper posterior and its lower edges 

 retrosely serrate ; the soft rays extending considerably beyond the spine, 

 1-& to 1 J in head ; adipose fin small, its base 3 to 4| in head, its height If 

 to 2 in its base; caudal widely forked, the upper lobe, measured from 

 base of caudal to its tip, the longer, about 1J in head ; base of anal If to 

 If in head, its longest ray 2-J- to 2 in head; ventrals reaching | to | the 

 distance to origin of anal; vent about midway between origin of ventrals 

 and origin of anal; pectoral spine 1 in head, serrate, the serrse on inner 

 edge larger and sharper than those on outer, the upper anterior serrae 

 tubercle like, the rays a little longer than spine. Bluish silvery, light yel- 

 lowish below; top of head and back brown; fins dusky olive, lighter at 

 base, all margined with darker; ventrals pale ; adipose fin covered with 

 minute black dots; maxillary barbels dark brown, with bluish silvery 

 luster; other barbels lighter; eye yellowish. Here described from 6 spec- 

 imens from San Juan Lagoon, mouth of Rio Ahome, Sonora, Mexico (No. 

 47584, U. S. Nat. Museum). Length 7i to 9 inches. 



Taehysuru* liropus, BRISTOL, in GILBERT, Proc. IT. S. Nat. Mas. 1896 (Feb. 5, 1897), 438, 

 San Juan Lagoon, near mouth of Rio Ahome, Sonora, Mexico. 



200(b). TACHYSURUS EMMELAJVE, Gilbert, new species. 



Head 3| in length (4^ in total) ; depth 5 (6 in total). A. 27 (3+24). 

 Eye 7 in head, 2 in its distance from tip of snout, 4 in postorbital part of 

 head, 3f in interorbital width, 2^ in frontal width opposite middle of 

 eyes. Mouth of moderate width, gently convex, the distance between its 

 angles (measured internally) 2J- in head. Teeth in preinaxillary and front 

 of mandible finely villiform ; posterior mandibular teeth stronger than 

 those in front, bluntly conic, not, however, granular or flat and pavement- 

 like, as are the posterior mandibular teeth in T. furthii, T. melanopus, and 

 T. liropus. Mandibular bands with a wide interspace mesially, each wid- 

 est near symphysis, rapidly tapering laterally, and extending beyond 

 angle of mouth. The width of the bands is less than in related species, J 

 eye at their widest point. The length of 1 of the mandibular bands is 

 slightly greater (IjV) than length of eye. Premaxillary band very short, 

 its length but greater than that of 1 of the mandibular bands, extend- 

 ing on each side less than $ distance from median line to angle of mouth; 

 width of band its length. Palatine teeth granular, in small oblance- 

 olate patches, which taper to a point laterally, and are widely separated 

 on medial line, the patches agreeing in size and shape with those in 

 T. liropus. Head depressed, tapering and at the same time narrowing 



