92 DIODONTID.E. 



or rays Interlace and cross each other in a curious reticulated manner. On the 

 sides and back the root extending forwards is the longest ; but on the breast and 

 belly they are all three equal. On the nape some of the spines have four or even 

 five-rayed roots; and the last upon the back, behind the dorsal fin, has only tv^ro, 

 placed astride over the fleshy root of the tail. The lips and muzzle before the 

 eyes, and the fleshy base of the caudal fin, are the only parts unfurnished with 

 this armour. 



The branchial opening is a single semi-lunar vertical cleft, furnished with a 

 loose valvular skin or border within, close before the base of the pectoral fin, 

 which is very large and broad or rather vertically oblong, deeper than long, and 

 placed high up the side on a level with the eye at about one third of the distance 

 from the muzzle to the root of the caudal fin. When expanded, its outer edge 

 foiTns a segment of a circle, and is quite even and entire. 



Dorsal fin seated on a sort of hump or pedicle near the hinder extremity of the 

 body ; subtriangular, and middle-sized. 



The anal fin nearly corresponds in position with the dorsal ; but is a little 

 backwarder, smaller, and more inclined to oblong. 



The caudal fin is small, trapeziform, simple, and truncate. 



The angles of the dorsal, anal, and caudal fins are rounded ; and the rays of 

 all are strong and broad, much branched and barred ; but buried and concealed 

 in a thick leathery skin. Their outer rays are more or less crooked or dis- 

 torted. 



It is almost needless to remark that all the rays are soft and flexible ; not 

 spinous. Yet both the first and last or outer rays in all the fins are simple or un- 

 branched. 



Upper half of the body with the whole head and fins, dusky, approaching to black 

 on the top of the head and back, and freckled or mottled with numerous distinct 

 small round black spots. Sides paler, greyish, with the spots larger and more 

 distant. Under lip, throat, breast, and belly, of a dead milky white, except a 

 dusky band extending across the throat like a cap-string : quite free from spots. 

 The iris is pale brassy, clouded with dusky brown. The whole inside of the 

 mouth is white. 



On dissection, the mass of the intestines and size of the whole fish appear 

 enormous when compared with the smallness of the fleshy part or muscle of the 

 body. The intestine is very voluminous and large. The air-bladder is large, 

 placed in the fore-part of the belly, with the parietes excessively strong and thick, 

 or almost cartilaginous, opaque, and of a pearly or satiny white : deeply bilobed for- 

 wards, or like two pears joined together sideways in their thick broad pails ; with 

 a singular round convex or lid-like protuberance at the broad hinder end. I could 

 not discover any communication or canal between it and the gixUet. It is tied to 

 the backbone by strong fibrous sinews proceeding from the fork of its two ovate ob- 

 tuse lobes on the upper side. The membrane which lines the air-crop above-men- 

 tioned becomes, when dried, of a fibrous cottony consistence. The vertebrae were 

 twenty-two, including, as usual, that from which originate the caudal fin-rays : 

 all had large, broad, foliated apophyses beneath. Their substance, though soft, is 

 truly fibrous ; and they are remarkably white. 



The weight of this fish, notwithstanding its paucity of flesh, is very 

 great in proportion to its bulk or length. The example here figured, 

 which was also the largest I have seen, and measured twenty-five inches in 

 length, weighed sixteen pounds and a half. The air-bladder is figured 

 proportionally reduced. 



