Classification of the Order Ostarioplysi. 



563 



Akysis and Acrochordonichthys resemble them in their air- 

 bladder and anterior vertebrae {fide Bridge and Haddon). 

 There is a skeleton of Akysis major, Bouleng., in the 

 British Museum collection^ but unfortunately this is a species 



A. B. C. 



A. Clnrins anguillaris. B. Clarotes Iceviceps. C. Liohagrus andersonii. 



Hyopalatine bones of the left side, seen from below, j^a^, palatine ; pt, 

 pterygoid; ms, mesopterygoid ; mt, metaplerygoid j q, quadrate; 

 hm, hyomandibular ; pop, praeoperculum. 



of Glyptosternum,^\n\s,t Koschkaroff's description and figures 

 of the skeleton of Akysis are evidently based on a species of 

 Macrones or some related genus. 



Family 9. Sisoridae. 



Differ from the Bagridse in certain features of specializa- 

 tion, such as the absence of pterygoid and post-temporal, the 

 contraction of the head of the hyomandibular, which articu- 

 lates with the sphenotic only, and the division of the air- 

 bladder into two lateral sacs. Lower surface of head and 

 abdomen flat and paired fins horizontal. Nostrils close 

 together, with a more or less developed barbel between 

 them. Gill-membranes free {Nangra, Bagarius) or attached 

 to isthmus. Vertebrae 34 to 40 (15-19 + 19-23) ; parapophysis 

 of the fourth vertebra a lamina which is decurved anteriorly, 

 forming a semicylinder ; parapophysis of the fifth vertebra 

 very strong, extending outwards to the skin, rarely uniting 

 with that of the fourth to form a complete cylinder. 



Asiatic fresh-water fishes. 



