FAMILY, I— SILURID^. 476 



SYNOPSIS OF SPECIES. 



1. Olyra longicaudata, D. 7/0, A. 23. Jaws of equal length. Caudal lanceolate. Kliasya hills. 



2. Olyra Burmanica, D. 8/0, A. 16. Jaws of equal length. Caudal lanceolate. Pegu hills. 



3. Olyra laticeps, D. 6/0, A. 1.5. Lower jaw the longer. Caudal rounded. Khasya hills. 



1. Olyra longicauda. 



McClelland, Cal. J. N. H. ii, p. 588, pi. xsi, f. 1 ; Bleeker, Beng. p. 58 ; Giinther, Catal. v, p. 98. 

 B. vi, D. 7/0, P. i V. 6, A. 23, C. 12. 



Jaws of equal length. Barbels — eight. Fins — pectoral, preceded by a rough spine. The middle rays of 



the caudal prolonged to a lengthened point. Air-vessel — membraneous, and placed in the anterior part of the 

 abdomen. 



Habitat. — Khaysa hills. 



2. Olyra Burmanica, Plate CXI, fig. 5. 



D. 8/0, P. i, V. 7, A. 16 (A), C. 17. 



Length of head 7|, of caudal 3, height of body 7? in the total length. Eyes — small, subcutaneous, and 

 in the anterior half of the head, above the level of the angle of the mouth. Jaws of nearly equal length, head 

 depressed. Nostrils patent, wide apart, the posterior with a barbel in front of it, the anterior just over the 

 .snout, but not in front of it. Gill-openings wide, not confluent with the isthmus, and extending laterally to 

 opposite the end of the opercle. Barbels — eight, not dilated at their bases, the maxillary are the longest, almost 

 extending to the base of the ventral fin, the external mandibular as long as the head. Teeth — villiform in both 

 jaws, the outer row shghtly the longest ; in an uninterrujjted horse-shoe shaped band across the palate. Lateral- 

 line — present. Skin smooth. Air-iiessel — large, thin, and in the abdominal cavity. Fins — dorsal without any 

 spine, its first ray the shortest, it arises opposite the ventral : adipose dorsal very low and long. Pectoral spine 

 rather strong, slightly serrated externally, coarsely so internally, the fin only extends half way to the ventral. 

 The anal rays increase in length to the last. Caudal with its central rays strongest and elongated, making the 

 fin one third of the total length. Colours — dark brown. 



Habitat. — Pegue Tomas or Mountains. 



3. Olyra laticeps. 



McClelland, C. J. N. H. ii, p. 588, pi. xxi, f. 2 ; Bleeker, Beng. p. 58. 

 ♦ Branchiosteus laticeps, Gill, Proc. Boston, Nat. Hist. Soc. 1862, p. 52 ; Giinther, Catal. v, p. 98. 



'B. xiH, D. 6/0, P. i V. 7 (6 ?), A. 15, C. 18. 



Eyes — small and vertical. Head much depressed at the snout. Lower jaw longer than the upper. Six 

 or eight slender barbels. Teeth — villiform in the jaws, palate edentulous. Fins — the anal rays gradually 

 increase in length from the commencement of the fin. Caudal entire. 



Habitat. — Khasya hills. 



Genus, 12 — Callicheous, Ham. Buch. 



Oinpok, Lacep. : Kryptopterus,* Kryptopterichthys, Micronema, Phalacronotus, Hemisiliirus, SHurodes, 

 Pseudosilurus, and Silurichthys, Bleeker : Pterocryptis, Peters. 



Branchiostegals twelve to fifteen. Gill-openings wide, the membranes not confluent with the skin of the isthmus, 

 are deeply notched and overlap. Head covered with. skin. Cleft of mouth oblique, not extending so far as the front 

 edge of the eyes : the lower jaiv the longer. Eyes subcutaneous, situated behind and opposite the angle of the mouth, 

 lateral or sometimes partially on the lower surface of the head. Barbels four or two, one maxillary, ami some distmice 

 behind the symphysis a mandibular pair, the latter sometimes being rudimentary, or even absent. Nostrils remote 

 from one another. Teeth villiform in the jaws, in an uninterrupted (SHurodes, Bleeker) or interrupted (Galliehrous, 

 Bleeker) band on the vomer, none on the palatines. Dorsal fin spineless, short, rudimentary, or absent, ivhen present 

 anterior to the venirals : no adipose fin. Pectoral with a spine. Anal long, continuous with (Pterocryptis, Peters) 

 or terminating close to the caudal, the latter being forked, emarginate or rounded. Ventral with eight to ten rays. 

 Air-vessel rather small, attached to the loiver surfaces of the second to the fourth vertebne, and 7iot enclosed in bone. 

 No axillary pore. 



* The Genus Kryptopterus, Bleeker (omitting the consideration of the barbels) separates those species wherein the dorsal fin is 

 rudimentary or absent from others in which it is short, being in fact a question of degree. Such being so, I think it preferable not to 

 subdivide them. Pterocryptis, Feters, forms perhaps a more natural genus, the anal being united to the caudal, but such a character 

 has not been deemed of sufficient importance to warrant dividing the species of Ooboides (p. 316), or Mastacembehis (p. 3.39) consequently 

 I have not adopted it here. It is curious that if genus Krytopterus were accepted, Professor Peters' Gangetic species with its 

 rudimentary dorsal fin would pertain to such, whereas my Indus one having that fin more developed would belong to CaXliclwoxis. The 

 only example of a CrypUypterus recorded from India, is Professor Peters' fish, this is interesting as it seems a form usually found 

 more to the eastwards. 



3 p 2 



