15 



Gladius — 



(a.) Eight feet long. Stuffed. Indian Ocean. Type of species. 



(b.) Seven feet long. Stuffed. Cape of Good Hope. 



(c.) Dorsal fin. New South Wales (?). Presented by Dr. G. 



Bennett. 

 (d.) Snout. Dried. 



In quoting the numerous authorities describing the species, Dr. Giinther, 

 amongst others, includes : — Penn., British Zool., iii., p. 216, pi. 30 ; Knox, 

 Edin. Journal ; Nat. and Geo. Society, ii., p. 427. 



Thus the material for scientific observation in the British Museum is 

 extremely limited, with regard to the XipJdidce. I may here remark, that in 

 my brother's (the late Professor Robert Knox) description, the comparative 

 anatomy would, to a certainty, be given ; and if so, I would have thought Dr. 

 Giinther would have availed himself of it. 



INTEGUMENTARY COVERINGS AND DERMAL PRODUCTIONS. 



The portion of the integuments, placed in the Museum, occupied the 

 anterior part of the dorsal line, corresponding to the neck, reaching from the 

 head, to and past the dorsal fin. I observed no appearance of sciles ; the 

 whole resembling coarse leather, and so formed as to require a saw to cut it. 

 The tissue thus forms a regular coat of mail made of spiculi of bone so inter- 

 woven with the integumentary tissues, as to be completely concealed. I should 

 consequently, imagine this fish to be perfectly secure from any enemy, in or out 

 of the water. 



The dorsal fin is, undoubtedly, a striking feature in the Xiphiidce, and the 

 caudal fin, in the specimen to which I have alluded in my brother's collection, 

 was also prominent. At a first view, it was as if formed of two dorsals, and 

 if included in the length of the fish (which is generally done by naturalists), 

 would have added a foot or more to the total length. 



By the very limited observation I could make on the specimen now under 

 review, owing to the non-scientific dissection it had been subjected to before 

 I got it, I found the dorsal tin capable of being moved,- to a very considerable 

 extent, in all directions. The interspinal processes (b, Plate 1) are firmly 

 united to each other, presenting a free articular surface to the rays of the tin ; 

 and when acted upon by the powerful muscles of the back, will act as a sail, 

 and an oar, the bi'ain being the steersman, the tail, no doubt, answering the 

 cerebral instinct, voluntary or not. The longitudinal fissure seen in the 

 specimen is not the result of dissection, but rSttural ; and is lined by a delicate 

 soft membrane, a continuation of the same covering immediately investing the 

 rays of the fin. The spinous processes of the vertebrae, when examined, will 

 be 'found bifurcated (c, Plate 1), forming a groove or slide for this unique 

 action of the dorsal fin in the Xiphiidce. In many fishes, however, the spinous 

 rays can be depressed, and again erected, at the will of the fish. 



The following measurements and weights of the specimen now deposited 

 in the Colonial Museum, were observed before and after their preparation : — 



lbs. oz. 



Weight previous to dissection : — Head, in- \ 

 eluding anterior half of the dorsal fin, but V 29 8 

 without any portion of the bronchial apparatus ) 



Lower jaw . . . . . . .28 



Total weight 32 



