1849.] Catalogue of Malayan Fishes. 1403 



She had four foetus, each \\ inch in length, in colour and form re- 

 sembling the mature fish. But the vertical diameter is in the foetus 

 proportionally greater. In the Straits of Malacca this species is at all 

 seasons very numerous. 



The electric organs (PI. XII. Fig. 1, a. a.) are of an elongated tetra- 

 gonal arched form, and occupy the sides of the disk. They occupy 

 the space between the snout and the abdominal cavity, their internal 

 concave margin bordering the branchial apertures. The length of each 

 is a little more than J of the length of the fish, and each occupies a 

 space about double that of the abdominal cavity. Each organ is com- 

 posed of a number of pentagonal or hexagonal cells, filled with a trans- 

 parent colourless fluid. The anterior and external margins are sur- 

 rounded by a bundle of cartilaginous fascicles (6.), outside of which 

 appears a long cutaneous nerve (c), from which proceed at right angles 

 a number of small branches towards the external margin of the pectoral 

 fins. The abdominal cavity (d.) is remarkably reduced. The intesti- 

 nal canal, from the entrance of the Ductus coledochus, measures % of 

 the total length of the fish. The liver consists of two large, elongated 

 lobes. Beneath the anterior part of the right lobe appears the small 

 oval gall-bladder. The small linear spleen is attached to the major 

 arch of the stomach, close to the pylorus. 



Plate XII. Fig. 2 represents the brains, viewed from above. Imme- 

 diately behind the spiracles («. the left,) appear two branches of Trige- 

 minus. The anterior (b.) proceeds along the anterior margin of the 

 electric organ, the posterior (c.) also supplies the anterior part of the 

 organ. The posterior part of the organ is supplied by two very large 

 branches of Pneumogastricus (d. e.). 



Many of these fishes are infested by minute Entozoa. They occupy 

 the cellular tissue immediately beneath the integuments of every part 

 of the body, the electric organs not excepted. It is a Cysteocercus, 

 barely perceptible to the naked eye. 



Cysteocercus temerj:, Cantor. (PI. XII. Fig. 3.) Ofapyri- 

 form shape. From the oval bladder proceeds the conical, elongated 

 neck, which terminates in a pore, surrounded by recurvous spines. The 

 colour is hyaline with numerous brownish dots ; the cavity of the blad- 

 der is pale greenish. The figure is magnified, as it appeared under -}-$ 

 single lens. 



