2784 BuUctiiL //, United States National Museuvi. 



200. TACHYSURUS MELANOPUS (Giinther). 



i). I, 7; A. 21; P. I, 10. The lieiglit of the body is contained 5 times in 

 the total length (without caudal), the length of the head 4^ times; head 

 somewhat broader than high, its greatest width lieing f of its length; the 

 occiput and nape are finely granulated; occipital process subtriangular, 

 as long as broad, Avith the lateral margins somewhat concave, and with 

 the median ridge a little elevated. The longitudinal groove in the mid- 

 dle of the crown of the head is indistinct, narrow, linc^ar behind, scarcely 

 extending to the base of the occipital process. The teeth on the palatines 

 are obtusely conical, and form 2 rather small subovate patches, apart 

 from each other, and situated on the front jiart of the palate. The max- 

 illary barbels do not quite extend to the middle of the pectoral fin. Dor- 

 sal spine of moderate strength, scarcely serrated anteriorly, equal in 

 length to the distance of the gill opening from the anterior margin of the 

 orbit, or even somewhat shorter; adipose fin small, the length of its base 

 being less than that of the dorsal ; pectoral spine nearly as long and 

 strong as that of the dorsal fin, very strongly serrated anteriorly. Porous 

 axillaries nearly as '\\-ide as a nasal opening. The upper (inner) surface 

 of the A'entral fins deep black, the lower (outer) white; the inner sur- 

 face of the pectorals blackish. Kio Motagua (east slope), a-b. From 8 

 to 9 inches long. From Mr. Salviu's collection. ((Tiinther, Cat., Y, 172.) 

 The specimens from the I'acific Coast mentioned in the text (page 132) 

 belong to the following sijecies. 



200(a). TACHYSURUS LI ROPUS, Susan P.. Bristol. 



Head .S? to 3|; depth 4?^ to 5,V. D. I, 6; A. II, 19; P. I, 9 or 10. Body 

 elongate, its Avldth anteriorally a little less than depth, the posterior 

 portion much (compressed; back elevated at front of dorsal; anterior pro- 

 file from front of dorsal to tip of snout oblique ; head flat, very broad, 

 its width \\ in its length; snout broad, rounded, 1,1,, to \\ in interorbital 

 width; eye rather large, laterally placed, its width a])out 1? in its length, 

 4^ to 4iHi in head; mouth small, upper jaw considerably projecting, its 

 breadth 2^' to 3 in head; jaws thin; wide bands of minute pointed teeth 

 present on both jaws; vomerine bands widely separated, and indistin- 

 guishable from the palatine baud, which is small, oblong-ovate, and 

 scarcely prolonged backward ; interval separating vomerine bands about 

 2\ or 3 in eye; the teeth on these bands larger than those on jaws, and 

 very bluntly conical. Interorbital space broad, 21 to 3 in head. Barbels 

 long and slender, the m.axillary barbel extending to, nearly to, or, in 

 some cases, past base of pectoral, ly'^ to l? in head; outer mental barbel 

 \\ to If in head; inner mental barbel 2^ to 2| in head. Antedorsal 

 shield very short, narrowly crescent-shaped, its length on the median line 

 about 2 or 3 in its width ; occipital process subtriangular, a little longer 

 than broad at base, its edge slightly concave, its median keel strong. 

 The long, narrow groove of the fontanel beginning abruptly a short dis- 

 tance in front of occipital keel, the distance from its end to base of dorsal 

 If to 2 in the distance to tip of snout. Shic^lds of head rather smooth, 

 finely granular, the granules forming distinct lines anteriorly. The flat 



