NATURAL SCIENCES OF PHILADELPHIA. 505 



decurvata, spinis 12 ; secunda p. anali rnajori, radiis I. 26. Squarnse miaimae, 

 serie longitudinali 170 plus minusve. 



Body elongated and scarcely compressed, with the back as well as the ab- 

 domen more or less rounded. Scales of the body very small, there being 170 

 in a longitudinal row in the typical species. Head elongated-conical, com- 

 pressed, gradually and nearly uniformly decreasing in width to the snout; eyes 

 moderate and submedian. Mouth small ; the periphery of each jaw semi-oval ; 

 jaws subequal, or lower shortest. First dorsal fin declining from the an- 

 terior portion in a straight or convex line, and with twelve spines. Second 

 dorsal longer, and with more rays than the anal (I. 26.) Anal fin with one 

 slender spine, and about twenty-two branched rays. Caudal fin emarginated. 

 Ventral fins with a slender spine. 



Type. Sillaginodes punctatus, Gill. 



The most apparent distinctive characters of this genus are the small size of 

 the scales, and the inequality, in size and number of the rays, of the second 

 dorsal and anal fins. Although the second dorsal fin of the typical Sillagines 

 is sometimes longer than the anal fin, the number of its rays is always the same 

 or nearly so, and only in the Sillago ciliata is the dorsal longer than the anal. 

 One species is known. 



Sillaginodes punctatus, Gill. 



Sillago punctata Cuv. et Vol. Hist. Nat. des Poissons, torn. iii. p. 413. 

 Habitat. Australia. 



SILLAGINOPSIS, Gill. 

 Synonymy. 

 Sillago sp. Cuv. et Val., Giinlher. 



Diagnosis. Dentes velutini, serie externa majores. Pinna dorsalis anterior 

 spinis 9, spina secunda elongata, postice oblique incurvata. 



Body elongated and subcylindrical. Scales small. Head elongated, depressed 

 and declining towards the snout in a nearly straight line : its width gradually 

 becomes less towards the nostrils, and thence the snout is more attenuated and 

 rounded at its end ; eyes very small and placed in the anterior half of the head. 

 Mouth small. Lower jaws shorter than the upper. Teeth of the jaws pluri- 

 seral, larger in the external row. Spinous dorsal fin commencing above the 

 pectorals, with nine rays, the second of which is much elongated ; second dor- 

 sal elongated, with its height gradually decreasing. Anal fin shorter than the 

 soft dorsal, and nearly co-terminal with it. Caudal fin emarginated. Ventral 

 fins with a slender spine. 



Type. Sillaginopsis domina, Gill. 



Syn. Sillago domina Cuv. et Val. 



This genus is very distinct from either Sillago or Sillaginodes, and is distin- 

 guished from both by the depressed head, the small eyes, the larger outer row 

 of teeth, and the form of its first dorsal fin. 



A single species is known. 



Sillaginopsis domina Gill. 



Sillago domina Cuv. et Val. Hist. Nat. des Poissons, torn, iii, p. 415, pi. 69. 

 Habitat. Bay of Bengal and East Indian Archipelago. 



Description of a new species of SILLAGO. 

 Sillago parvisquamis Gill. 



The body is slender and highest under the first dorsal fin, the height there 

 equalling an eighth (12-100) of the total length ; under the second, it gradu- 

 ally diminishes, and the height of the constricted caudal peduncle is only a 

 twentieth (5-100). The greatest width nearly equals a tenth of the length; 

 behind, it becomes regularly compressed to the caudal fia. 



1861.] 



