Jordan and Ever manji. — 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 pnpil; opercles with no radiating strije. Gill membranes forming 

 a very narrow fold across the isthmus. Gill rakers 5 + 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, \ery short, 4 to 5^ in pectoral spine. Base of dorsal 2? to 2{\^ in 

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

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

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

 Ig to \\ in head; adipose fin small, its base 3^ to 44^ 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 \\ in head; base of anal If to 

 If in head, its longest ray 2^ to 2^ in head; ventrals reaching % to | the 

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

 an<l origin of anal; jiectoral spine li in head, serrate, the serric on iniier 

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

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

 lowish below; top of head aud back brown; tins dusky olive, lighter at 

 base, all margined with darker; ventrals pale; adipose hn 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 .Tnan Lagoon, mouth of Eio Ahome, Sonora, Mexico (No. 

 47584, U. S. Nat. Museum). liength 1\ to 9 inches. 



Tachysuriis Hropus, Bristol, in Gilbekt, rroc. U. S. Nat. Mns. 1896 (Feb. 5, 1807), 438, 

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



200(b). TACHTSURUS EMMELANE, Gilbert, new species. " 



Head 3| in length (4iV 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 jiostorbital part of 

 head, 3| in interorbital width, 2i in frontal width opposite middle of 

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

 angles (measured internally) 2^ in head. Teeth in premaxillary and front 

 of mandible tinely 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. fnrlhii, T. mclanopm, and 

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

 est near symphysis, rapidly tapering laterally, and extending beyond 

 angle of month. The width of the bands is less than in related species, I 

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

 slightly greater (Ir'n) tlian length of eye. Premaxillary band very short, 

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

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

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

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

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

 T. liroj)iis. Head depressed, tapering and at the same time narrowing 



