OCR Text |
Show 712 SURGEON F. DAY ON THE [Dec. 5, PLOTOSUS CANIUS, H. B. pl. 15. f. 44. Air-vessel of moderate size, placed transversely across the anterior vertebrae. Its external fibrous coat is thick, whilst internally it is divided by a longitudinal septum into two lateral cavities, which communicate anteriorly by a large circular opening. Geographical distribution. - This genus contains marine and estuary fishes; but P. canius is sometimes captured in fresh water. The genus has a very extensive range, being found in Africa, Asia, through the Indian seas to the Malay archipelago, and even beyond it. CLARIAS MAGUR, H. B. pl. 26. f. 45. Air-vessel tubular, placed transversely across the body of the anterior vertebrae, where it is entirely enclosed in a bony capsule. This subject is remarked upon in Cuv. and Val. Geographical distribution.-The genus is found in Africa, India, Ceylon, Burmah, throughout the Malay archipelago, even to beyond it. SACCOBRANCHUS FOSSILIS, Bl. Silurus singio, H. B. pl. 37. f. 46. Air-vessel small and situated transversely across the body of the anterior vertebrae, either extremity being enlarged, globular, and enclosed in a bony capsule. Cuv. and Val. remark upon this. Geographical distribution.-The genus extends through India, Ceylon, Burmah, and, according to Dr. Gunther, Cochin China. SILUNDIA GANGETICA, CUV. et Val. Pimelodus silondia, H. B. pl. 7. f. 50. Air-vessel small and placed transversely across the body of the anterior vertebrae, where there is a groove to receive its posterior surface; anteriorly it has a thick, strong, fibrous covering. There is a low osseous process from the vertebra, giving it protection laterally. The air-vessel itself consists of two small oval portions, having a median connecting tube; and this lateral part is surrounded by osseous or strong fibrous walls. Geographical distribution.-Large rivers of India and Burmah. AILIA BENGALIENSIS, Gray. Air-vessel as in the following genus. Geographical distribution.-Rivers of the plains of India (except in Madras), extending to the upper portions of the Ganges and Jumna, but not on to the hills; also Assam. Genus AILIICHTHYS, gen. nov. Differing from Ailia in that the ventral fins are entirely absent. Geographical distribution.-The Jumna, and southern rivers in the Punjaub that are tributaries of the Indus, but not those on the hills. |