Jordan and Evcrmann. — Fishes of North America. 2761 



process wider than long, scarcely keeled. Fontanel not continued behind 

 the eyes, and withou backward projecting groove; posterior nostrils 

 connected by a membrane. Barbels ilattish, those of the maxillary reach- 

 ing to near the ventrals, to middle of pectorals in older individuals; 

 postmeutal to or beyond base of pectoral, mental to gill opening. Teeth 

 villiform; vomerine and palatine patches of about equal size and shape 

 in the young; a separate patch behind the palatines is developed later. 

 Gill membranes meeting in an angle, forming a fold across the isthmus ; 

 gill rakers 6 + 10. Distance of dorsal spine from snout 2\ to 2| in the 

 length; dorsal and pectoral spines subtereto, the outer margins rough- 

 ened, the sides striate; the dorsal spine slightly serrate behind, a little 

 shorter than the pectoral spine, \\ to 13 in the head; pectoral spine 

 strongly serrate behind; space between dorsal and adipose fins 3f to 4 in 

 the length; adipose fin as long as the dorsal; upper caudal lobe longer, 

 about 4 in the length; anal as high as long, 2 in head; ventrals If to 2 

 in head; pectoral pore minute; sides with vertical series of pores. Color 

 plumbeous above, silvery on sides; fins dusky. The specimens exam- 

 ined measure from 0.14 to 0.38 meters. Para; Curuca; Bahia. (Eigenmanu 

 & Eigenmann, Nematognathi, 59.) 



174. SELEXASPIS DOWII (Gill). 



Head 3i; depth 6. D. I, 7; A. 19; eye small, elliptical, 3 in snout, 12 

 in head, 6 in interocular. A narrow flap of skin across the snout con- 

 necting the posterior nasal openings. Width Ijelow the dorsal spine a 

 little greater than the depth, less than the width at the humeral process, 

 Avhich e(iuals the greatest width of the head measured at the opercles. 

 Head depressed, its depth at base of occipital process 1^ in the greatest 

 width, becoming gradually more depressed forward; width at angle of 

 mouth 1| in length of head, its greatest width about \\ in its length; 

 snout short, 4 iii head. Top of head coarsely granular, the granules 

 forming stria- in front, verraiculatious posteriorly or, in places, more or 

 less regular stria>. Occipital process truncate, its width at tip greater 

 than its length, the dorsal plate large, saddle-shaped, its bony tubercles 

 forming striic which are parallel with the strongly convex margin of the 

 "saddle"; opercular bones granular striate, the humeral process with 

 bony tubercles. Fontanel nearly obsolete, the granular bony surface 

 being separated in front by thick skin, which covers an elongate area 

 about 7 times longer than wide. Maxillary barbels reaching beyond 

 humeral process; postmental barbels beyond gill opening, the mentals 

 shorter. Ujjper jaw produced, equal to the short diameter of the eye. 

 Teeth oi the lutermaxillaries in a villiform band which is narrowed in 

 front, not produced backward to the angle of the mouth ; vomer with a 

 rather broad band confluent with the much wider subquadiate palatine 

 patches which are produced backward in an angle; ovate patches on the 

 pterygoids separate from the palatine teeth; teeth of the lower jaw in a 

 comparatively shallow band, tapering very gradually to the angle of the 

 mouth; the teeth of the jaws minute villiform, those of the palate and 

 3030 96 



