170 TELEOSTEI. PHTSOSTOMI. 



of Oxteoyeniosus, with from 15 to 20 eggs in their mouths. Some 

 of these eggs were in an early stage of development, others nearly 

 ready to be hatched ; while in the mouth of one specimen was a 

 hatched fry having the yolk-bag still adherent. The eggs filled the 

 cavity of the mouth and extended far back to the branchiae. 



In the female organs of generation the eggs seemed to come to 

 maturity in batches of perhaps 50 at a time. On examining the 

 conformation of the ventral fins, those of the females appeared to 

 be larger than those of the males ; the rays were thickened by a 

 deposit of fat, whilst the innermost one had a large pad attached 

 to its posterior edge. These fins can be expanded into a cup-like 

 surface, the use of which may be to receive the eggs as extruded, 

 which may be vivified there by the male. 



Whether the male carries about these eggs in his mouth until 

 hatched or only removes them when danger is imminent from some 

 spot where he is guarding them is questionable, but in none of the 

 specimens which I examined did I find a trace of food in the 

 intestines of the males which had been engaged in this interesting 

 occupation. 



This has been observed likewise elsewhere by Mr. Boake in 

 Ceylon, and Dr. Hensel has recorded the same of a Brazil species, 

 A. commersonii ; Dr. Gunther of Arias fissus from Cayenne ; and 

 the same facts have been remarked in other Siluroid fishes. 



Geographical Distribution. Seas and estuaries of tropical regions, 

 ascending to within tidal influence or even entering fresh waters. 

 Arius appears to be almost as unknown in the lied Sea as the 

 Sciceiiidce, and probably from the same cause. 



Uses. As food of an inferior quality. On the western coast of 

 India species of this genus are largely salted and a considerable 

 amount of coarse isinglass is procured for export to China by 

 drying their air-bladders. 



/Synopsis of Indian Species. 



A. Villiform teeth on the palate. 



A. 19-22. Head 3| to 3 in total length. 



Eye 7 to 8| in length of head. Mouth 



spatulate. One patch of teeth not as 



large as eye on either side of palate .... 1. A. burmanicus, p. 173. 

 A. 19. Head 4 in total. Eye 6 in length 



of head. Maxillary barbels reach last 



third of pectoral fin. Two triangular 



patches of teeth approximating superi- 



orly.' Dorsal spine as long as head. 



Dull yellow, fins blackish ............ 2. A. ne>u/a, p. 173. 



9 in length of Lead. Maxillary barbels 

 reach middle of pectoral fin. Two some- 

 what triangularpatches of teeth, approxi- 

 mating anteriorly. Dorsal spine about 

 as long as head .................... 3. A. ccelatus, p. 174. 



