CLELAISD OTT THE ANATOMY OP THE SHORT STTN-PISH. 171 



while, Oil the other hand, the greatest height, exclusive of fins?, 

 was 24 inches. The pointed dorsal and anal fins, which stood 

 out nearly at right angles to the body, nieasiu'ed each 16 inches 

 in length, and, at their broadest parts, near their bases, 8 inches, 

 from before backwards. 



Dermal Structures. 



The structure of the integument, which was about an inch 

 thick over the trunk, has been specially studied by Mr. Tiu'ner, 

 whose description will be found below. It is separated from 

 the muscles, and from the abdominal cavity, by a strong aponeurosis. 

 At the origins of all the fins it becomes soft and loose, so as to 

 allow of their free movement. On the dorsal, anal, and pectoral 

 fins, it is reduced to a thin membrane, very difficult to detach ; 

 but on the caudal fin it retains a considerable thickness, and the 

 caudal fin rays must be dissected out from the dense matrix of 

 integument in which they are imbedded, before their course can 

 be displayed. 



Besides the little spinous tubercles studded all over the skin, 

 there are several much larger sclerous tegumentary formations. 

 Arming the prominence which projects above the mouth, are one 

 large, and several smaller hard plates, as much as half an inch in 

 thickness ; and at the extremity of each caudal fin ray, is a half- 

 moon-shaped plate of the same kind, thick on the deep aspect, 

 and coming to an edge at the free margin. The deep asj^ects of 

 all these plates exhibit perforations of considerable size for vessels, 

 and an iiTegular arrangement of minute rounded projections. 

 The superficial aspect of those from the head is divided into 

 little areas, corresponding to the tubercles of the skin ; that of 

 the caudal plates presents tubercles, or sjiines, more irregular and 

 prominent than those on the general surface of the body. 



Tliere is exhibited, by a vertical section of one of these plates, a 

 closely set vertical series of large, irregular, and on all sides inter- 

 communicating tubes, whose outlines are visible even to the naked 

 eye, and which are imbedded in a hyaline matrix.— (Pt. V. fig. 3). 

 These tubes are most regularly disposed towards the deep aspects 

 of the caudal plates, and most irregularly toward the free 

 extremities of the same. In the latter situation they are seen 

 frequently expanding into large irregular dilatations, into which 

 several of them open from difterent directions. The spines upon the 

 surfaces of the caudal plates are composed of the same translucent 

 structure as those projecting from the tubercles on the surface of 

 the general integument, and show in section the same striated 

 appearance. Toward the deep aspects of these spines, the tubes 

 in the neighbourhood tend to converge by free extremities ; and 

 isolated portions of the same structure as that of which the tubes 

 are composed, are seen like large cells, or strings of cells, of various 



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