I 



104. EXOSTOMA. 265 



ously round the mouth, so as to form a broad flat sucker. Teeth in 

 two separate patches above and below, leaving a suctorial centre 

 between them ; palate edentulous. Head depressed, covered with 

 soft skin above ; eyes small. Gill-openings very small, not extend- 

 ing on to the lower surface of the head. Caudal fin forked ; pec- 

 torals horizontal, without adhesive apparatus between ; ventrals with 

 six rays, inserted below the end of the dorsal fin. 

 East Indian Continent. 



1. Exostoma labiatum. 

 Glyptosternon labiatus, 3r Ckll. Calc. Journ. Nat. Hist. ii. p. 588. 



D. 1/6. A. 6. P. 1/12. 



Head depressed, obtusely rounded, as broad as long, its length 

 being nearly one-fifth of the total (without caudal) ; eyes verj- small ; 

 mouth inferior, transverse, narrow, double crescent-shaped (^^) ; 

 the lower jaw surrounded by a broad flap-like lip, divided into a 

 median lobe and into a pair of lateral ones ; there is a very small 

 appendage in each notch between the median and lateral lobes ; these 

 appendages may be considered as a fourth pair of barbels. The 

 free portion of the tail is as high as long. The first dorsal ray 

 scarcely spinous. The distance between the dorsal and adipose fins 

 is two-thirds of the length of the latter. Caudal fin slightly forked, 

 the lower lobe being scarcely longer than the upper. The pectoral 

 and ventral fins are obliquely inserted, so that the inner rays are 

 situated above the outer ones ; the outer rays dilated, transversely 

 striated below. The pectoral terminates at a considerable distance 

 from the ventral. 



Mishmee Mountains (Assam). 



a. Type of the species : 3| inches long. From Mr. Griffith's Col- 

 lection. 



2. Exostoma berdmorei. 



Bli/th, Journ. As. Soc. Beng. xxix. p. 155. 



D. 1/6. A. 6. P. 1/10. 

 Maxillary barbels extending beyond the base of the pectoral ; 

 lower caudal lobe much broader and longer than the upper. Olive- 

 brown above, clouded with darker. (Blyth.) 

 Tenasserim (4 inches long). 



