42. BXOCLOSSUM. 187 



side on the uppei as well aa on the lower ja\r, exactlj' as in the genus 

 Tctraodon, their e^lge being sharp and cutting. The dorsal fin has 

 the structure of that of FimqJtales ; the insertion of the \-entrals is 

 situated under the anterior margin of the dorsal, the caudal being 

 furcated. The scifles are hn-ge, and the lateral line follows the 

 middle of the flanks ; the isthmus rather wide. The pharyngeals 

 have the same shape and form as in Piim pintles; the teeth, however, 

 are more slender and concave upon the grinding-surface, giving them 

 the appearance of being bent backwards : they are of the same 

 t} pe, a little more conspicuously hooked, 4 — 4. 

 Texas. 



1. Cochlognathus omatus. 



Baird S,- Gintrd, I. c. 1854, p. 158, and U. S. ^-Mex. Bound. Icht/ii/ol. 

 p. 40, pi. 35. figs. 12-17. 



D 9. A. 6. 



Head forming two-ninths of the entire length, and abruptly 

 rounded off" on the snout; mouth proportionately small and terminal, 

 with oblique cleft. Eyes rather above the medium size, their dia- 

 meter being contained four times in the length of the side of the 

 head. Body nuicli compressed, covered with large scales disjioscd in 

 twelve longitudinal rows on the line of greatest depth. Lateral line 

 inflexed downwards upoji the abdomen. Anterior margin of dorsal 

 nearly eqiudistant between the snout and rudimentary r;ivs of the 

 caudal; anal situated entiVcly backwards of the dojsal ; caudal 

 forked. Insertion of ventrals beneath the anterior margin of dorsal ; 

 tip of pectoral not reaching them. The colours, as preserved in 

 alcohol, present a reddish-brown ground, and a dark lateral band 

 or stripe. The dorsal fin exhibits two elongated dark spots, one 

 anterior and basal, the other posteiior and nearer to its tip. The 

 posterior half of the caudal has likesvise a darker hue than its ante- 

 rior and basal half, which is of a dull orange, as is also its extreme 

 margin. ( Girard. ) 



Brownsville ; Texas. 



4.2. EXOaiOSSUIfl. 



Exoglossum, Rajinesque, Jouni. Ac. <S'c. Nat. P/iilad. i. p. 419; Cui'. 

 i^- Viil. xvii. p. 480; Agassiz, Amer. Journ. Sc. i^- Arts, 1855, xix. 

 p. 215. 



Scales of moderate size, lateral line present and complete. Dorsal 

 fin short, without spinous ray, commencing above the ventrals; anal 

 fin short Mouth inferior, of moderate width; theupper jaw is snb- 

 semicircnlar in its outline, not protractile, provided with a thick 

 lip overlapping the lower jaw. The mandibles are united by a brond 

 symphysis extending along the entire length of the .lentary bones, 

 the symphysial portion being prominent, narrow, tongue-shaj;ed, 

 with a sharpish edge, destitute of a labial covering, the labial fold 

 being developed towaids the angle of the mouth only ; barbels none ; 

 ^ill-iakcrs ex ircnuly feeble : pseudobranchia'. The gill-cavity com- 



