30 



Second Subfamily. 



SILURID^ HETEROPTER^. 



The rayed dorsal fin is very little developed, and if it is present, 

 it belongs to the abdominal portion of the vertebral column ; the 

 adipose fin is exceedingly small or absent. The extent of the anal 

 is not much iaferior to that of the caudal vertebral column. The 

 gill-membranes overlap the isthmus, remaining more or less 

 separate. 



Fourth Group. SILURINA. 

 The ventral fins are behind or below the dorsal. 

 Old World. 



7. SACCOBRANCHUS. 



Saccobranchus, Cuv. <^ Val. xv. p. 399. 

 Heteropneustes, Mullet: 



Adipose fin none ; dorsal very short, without pungent spine, 

 placed above the ventrals; anal very long. Jaws and vomer with 

 bands of vUliform teeth ; cleft of the mouth transverse, anterior, 

 of moderate width ; barbels eight. Eyes rather small. The iipper 

 and lateral parts of the head osseous, or covered with a very thin 

 skin. GUI-membranes separated by a deep notch ; gill-cavity with 

 an accessory posterior sac, extending backwards between the muscles 

 along each side of the abdominal and caudal portions of the vertebral 

 column. Ventrals six-rayed. 



East Indian continent and Ceylon. 



1. Saccobranchus singio. 



Silm-us singio, Ham. Buck. Fish. Gang. pp. 147, 374. pi. 37. fig. 46. 

 Saccobranchus singio, Cuv. 4" Val. xv. p. 400 (pi. 448*). 



B. 7. D. 6-7. A. 68-70. P. 1/6. V. 6. 

 The height of the body is contained seven times and a half in the 

 total length (without caudal), the length of the head (to the end of 

 the operculum) six times and a third. Eye of moderate size, about 

 half as long as the snout. The maxillaiy barbels extend to, or some- 

 what beyond, the extremity of the pectorals. The distance of the 

 dorsal fin from the end of the snout is rather less than one-third of 

 the total length (without caudal). Pectoral spine rather strong, its 

 length being three-quarters of that of the head; the ventral fin 



* This plate may represent a specimen of S. fossi/is. 



