VOL. LXXXIII.] PHILOSOPHICAL TRANSACTIONS. 2S5 



It has 6 fins : 2 pectoral, 2 ventral, idorsal, and 1 anal fin. The tail is broad, 

 and of a triangular form. The pectoral fins are small, blunted at their ends, 

 and placed a little behind the gills. The ventral fins are placed on the sternum, 

 and are longer, and more pointed. The dorsal fin arises at the beginning of the 

 spinous processes of the back, and is continued down nearly to the tail. The 

 anal fin arises a little below the anus, and is also continued on almost to the tail. 

 It is strong and broad, like the dorsal, and projects a little farther backward 

 than it. 



The mouth is small, and each jaw contains 5 rows of small teeth, about the 

 thickness of hog's bristles, and of equal thickness throughout their length. 

 The grinding, or cutting surfaces of the front, 2d, and 3d rows, in both jaws, 

 are divided into 3 points. The 2 inner rows are pointed, and bent a little back- 

 ward. The stomach was empty, so that there was no opportunity of ascertain- 

 ing its food. The intestinal canal was long, like that of fish which feed on 

 vegetables ; and the oesophagus was thick set with pyramidal bodies, like the 

 oesophagus of the turtle. The skeleton is very singular, many of the bones 

 having tumours, which, in the first fish Mr. B. saw, he supposed to be exos- 

 toses arising from disease ; but on dissecting a second, found the corresponding 

 bones had exactly the same tumours, and the fishermen informed him they were 

 always found in this fish ; he therefore concludes them to be natural to it. 



In Mr. Hunter's collection are 2 or 3 of these bones, but Mr. B. never knew 

 what fish they belonged to; they were supposed to be from the back of some of the 

 large rays. What advantage can arise from these large tumours is difficult to 

 say. Those on the spines of the vertebrae seem to answer no evident purpose, 

 nor those at the origin of the dorsal, and anal fins. The particular form of the 

 sternum, to which the ventral fins are joined, seems to be intended to give 

 greater surface for the attachment of theunuscles, and to increase their action. 

 These tumours are spongy, and so soft as to be easily cut with a knife ; they 

 were filled with oil. The air-bladder is very large, for the size of the fish, pro- 

 bably to counteract the weight of the bony matter in the skeleton. It is gene- 

 rally caught near the shore, where there are sea-weeds, and the Malays say it is 

 a dull swimmer. PI. 3, fig. l, represents the fish; fig. 2, the skeleton of the 

 same. 



IV^. Account of some Discoveries made by Mr. Galvani, of Bologna ; ivith 

 Experiments aiid Observations on them. In livo Letters Jrom Mr. jilexander 

 Folta, F. R. S., Professor of Natural Philosophy in the University of Pavia, 

 to Mr. Tiberius Cavallo, F. R. S. p. 10. From the French. 



The subject of these letters, Mr. V. says, is that of animal electricity, dis- 

 covered by Dr. Galvani, and published by him in a work entitled, " Aloysii 



