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Show 782 MR. F. DAY ON THE FISHES OF YARKAND. [Dec. 5, With them I have compared some types of Steindachner's excellent paper on Dr. Stoliczka's 'Fishes of Tibet' (Verh. z.-b. Ges. Wien, 1866), which specimens were given m e 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 STOLICZKA. D. \, P. i V. \, A. 6, C. 15. Length of head from 4 in the young * to 5|, 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 nostril. Head depressed, as broad as long, and obtusely rounded. Mouth inferior ; lips thick, and studded with small tubercular elevations ; 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 maxillary 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 tbe 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 44, in the total length. 4 „ 4*2 to 4*5 „ „ 4^to5i 5 „ 5-0 to 5-7 „ „ 5 to5| 3 „ 60 to 6-6 „ „ 5£ to 5f 2 „ 7 „ „ 5£ to 5£ |