51 



189. The last abdominal and first three caudal vertebrae, vertically and longitudi- 

 nally bisected, of a Flat-fish (Plrttroccte$, Linn.) : showing the confluence of 

 the long liu-mol spines of the first two caudal vertebra;. lluntmnn 



100. The- basibranchial, hypohrnnchial and ceratobranchial pieces of a Flat-fish 

 (Plewrtmcctet) : showing the Inninrifonn denticles in the ceratobranchials of 

 the first four arches, and the close-set molars on the corresponding elements 

 of the fifth arch, constituting the ' inferior pharyngeal bonefc' 



Order V. ACANTHOPTERI. 



Family Pcrcida. 

 191. The skeleton of a large Sea-perch (CtHtroprufu giga*}. 



This skeleton well exemplifies the typical structure of the Aoanthopterygian division of 

 Otseou* Fishes in the system of Curier. All the rays of the first or anterior dorsal fin are 

 strong undivided osseous spines ; and the first rays of the anal and pectoral fins are formed 

 by similar spines. The formula of the fin-rays is: D. 11, 1 + 12; A. 3-1-9; C.19; P. 19; 

 V. I + 5 : that is, there are 1 1 spinous rays in the first dorsal (the fifth, sixth, seventh 

 and eighth being the longest, and the first ray not one-fourth the length of the rest) ; 

 1 spinous plus 12 soft rays in the second dorsal ; 3 spinous and 9 soft rays in the anal , 

 19 rays in the caudal ; 19 rays in each pectoral ; and 1 spinous plus 5 soft rays in each ven- 

 tral fin. 



The absence of any larger conical teeth amongst the denticles of the ru p-like bands which 

 roughen the alveolar borders of the premaxOlary and premandibular bones, removes the pre- 

 sent specimen from the Percoid genus to which the Serrantu giga* belongs; whilst tin- 

 forms of the opercular bones and the formula of the fin-rays distinguish it from any other 

 known specie* of the genus Centroprutu, to the characters of which, as defined by Curier, it 

 strictly conforms. 



The suborbital bones are five in number, including the anterior large one, or ' lachrymal ' 

 bone : the third bone has a broad orbital plate directed inwards and backwards. The prr- 

 operculum is exclusively suspended from the tympanic pedicle : its lower angle is rounded 

 and obtuse without any notch above it. The whole posterior border of this bone is finely 

 dentated ; the teeth at the angle being very little larger than the rest : the lower border is 

 more curved than in the Serramu gigat, and it is not festooned. 



The opercular bone terminates behind in two points, the lower one being the largest, 

 whilst in the Cntroprutu nigriraiu the upper one is the largest. A strong ridge croase* 

 the outside of the opercnlum ; the upper border of the bone is entire and convex. The 

 outer surface of the interopercnlar bone is excavated by broad but shallow depressions, as if 



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