782 MR. F. DAY ON THE FISHES OF YARKAN D. [Dec. 5, 



With them I have compared some types of Steindachner's excel- 

 lent paper on Dr. Stoliczka's 'Fishes of Tibet' (Verh. z.-b. Ges. 

 Wien, 1866), which specimens were given me by Dr. Stoliczka. 



Mr. Hume, C.B., has since then obtained a few more skins of 

 fishes from those regions through the exertions of Dr. Scully. These 

 have likewise been forwarded to me ; and one appears to be at present 

 undescribed ; it is a very aberrant form of Ptychobarbus. 



Order PHYSOSTOMI. 

 Family Silurid.e. 



1. EXOSTOMA STOLICZKjE. 



D.^P.l \.\, A. 6, C. 15. 



Length of head from 4 in the young * to 5f , of caudal 8, height 

 of body 7\ in the total length. Eyes minute, situated in the middle 

 of the length of the head ; the width of the interorbital space equals 

 half that of the snout, or the distance between the eye and hind nos- 

 tril. Head depressed, as broad as long, and obtusely rounded. 

 Mouth inferior ; lips thick, and studded with small tubercular eleva- 

 tions ; the upper and lower lips continuous at the angle of the mouth ; 

 but the transverse fold across the lower jaw is interrupted in the 

 middle. Nostrils close together, the anterior round and patent, the 

 posterior tubular : a barbel divides the two nostrils ; it is situated on 

 a bridge of skin, below which the two nostrils are continuous. 

 Barbels : the nasal ones reach the hind edge of the eye ; the maxil- 

 lary ones have a broad basal attachment, and reach the root of the 

 pectoral. Of the mandibular barbels the anterior are situated just 

 behind the inner end of the lower labial fold ; they are shorter than 

 the outer pair, which latter extend to the gill-opening. Gill-opening 

 situated on the side of the head in front and above the base of the 

 pectoral fin. Teeth : several rows of pointed ones in each jaw, of 

 which the outer is slightly the larger, rather wide apart, and with 

 rather obtuse summits. Fins : the dorsal arises midway between 

 the snout and the commencement of the adipose fin ; its greatest 

 height is one third more than the length of its base ; its spine is 

 rudimentary and enveloped in skin. Adipose dorsal very long and 

 low. Pectoral nearly as long as the head, having its outer half 

 horizontal and its inner vertical ; its spine is rudimentary, with a 

 broad, striated, cutaneous covering. Ventral of a similar form to 

 the pectoral ; its first and a portion of its second ray also with a 

 striated cutaneous covering ; the fin commences on a vertical line 

 falling just behind the base of the dorsal fin ; it is rather nearer the 



* The remarkable difference in the comparative length of the head to that of 

 the total length is shown in the following figures : — 



3 specimens 4 inches in length. Head 4 to 4^ in the total length. 



4 „ 4-2 to 4-5 „ „ 4£to5i 



5 „ 5-0 to 5-7 „ „ 5 to 5£ 

 3 „ 6-0 to 6-6 „ „ H to 5f 

 2 „ 7 „ „ 5£t.o5£ 



