65 



..MI! tubercle, and the extremity of the luemal ipine of the eighth caudal vertebra rx|Muid> 

 into i simiUr but smaller tubercle. The two pelvic bone* are expanded into pyriform tu- 

 bercle*, and four of the middle pain of rib* are similarly expanded, but in a slighter degree. 

 Tin- head* of the ribt articulate with deep cavities in the aide* of the bodies of the abdominal 

 vertebne. 



The teeth of the Plata* are very small and numerous, as in the rest of the Cha*todont 

 family, but are distinguished by their tricuspid summit*. 



Fig. Phil. Trans. Ixxxiii. tab. v. and vi. from this specimen. 



Habitat. The Indian Seas. 



Sent to England by William Bell, Esq., and presented to Mr. Hunter by Sir Joseph 

 Banks, Bart. 



" The skeleton is very singular, many of the bone* hating tumours, which, in the first fish 

 I saw, I supposed to be exostoses arising from disease ; but on dissecting a second, I found 

 the corresponding bones had exactly the same tumours, and the fishermen informed me they 

 were always found in this fish : I therefore conclude them to be natural to it. In Mr. Hun- 

 ter's collection are two or three of these bones, but I never knew wliat fish they belonged to ; 

 they were supposed to be from the back of some of the Urge Rays. What advantage can 

 arise from these Urge tumours is difficult to say. Those on the spine* of the vertebra* 

 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 the muscles, and to increase their action." 

 Extract from Mr. Btlft paper on tku juk, m tke ' Philosophical Transactions,' reiul 

 January \7th, 1/93. 



Htinterian. 



257. The premandibular and prcmaxillary bones of a Chatodont fish, which, from 

 the trifid character of the -uniiiiits of the teeth, belongs to the genus Plata*. 



The following are the Hiinterian specimens referred to by Mr. Bell : 



258. One of the expanded ribs of the Plata* artkritictu. Hu*t<ria*. 



259. The long interhsenial spine of the first caudal vertebra of the Plata* arthritic**, 



the distal extremity of which expands into a very large bony mass, and present* 

 articulations for the two anterior spines of the anal fin. II*nteria. 



260. The fourth caudal vertebra of the Plata* artkritictu ; showing the osseous 

 tubercle of its spinous process; small anterior and posterior zygapophyses, 

 forming accessory neural arches, are developed from its base. Htntterian. 



E 



