FISH. 123 



dorsal, and answering to it exactly. The ventrals are attached at a point, in this specimen, 

 about half an inch posterior to the middle of the entire length, reckoning this to the end of 

 the fleshy part of the tail ; but are not much out of the middle, if the length be reckoned to 

 the end of the upper lobe of the caudal : their length is contained not quite three and a half 

 times in the entire length, excluding caudal ; and they reach exactly to the end of the dorsal 

 and anal : first ray very much branched, and only one-third the length of the fin ; second ray 

 appearing like two or even three rays at its upper extremity, from the circumstance of the 

 several branches of it being of unequal length ; all the other rays branched likewise. Vent a 

 very little in advance of the anal. Upper lobe of the caudal one-third shorter than the 

 lower ; this last being exactly the same length as the ventrals. 



D. 11 ; A. 12 ; C. 16, &c. ; P. 18 ; V. 6. 



Length 12 inches 8 lines. 

 Colour. — The colours were not noticed in the recent state ; and the specimen is in such bad con- 

 dition, and so much altered by the spirit, that they are now no longer distinguishable. 

 The flying-fish above described was taken by Mr. Darwin in the Pacific 

 Ocean, off the coast of Peru, in Lat. 18° S. It appears to be the E. exsiliens of 

 Bloch, but as I am not aware that the species of Exoccetus have been ever rigour- 

 ously worked out, and closely compared from different parts of the globe, I have 

 thought it expedient to annex a description, by which it may be identified, if it 

 prove hereafter distinct.* 



Family.— SALMONID^. 

 1. Tetragonopterus Abramis. Jen. 

 Plate XXIII. fig. l. 

 T. corpore subrhomboideo, compressissimo, altitudine fere dimidium longitudinis, pin- 

 na caudali exclusd, tequante : osse maxillari angusto, retrorsum arcuato : pinna 

 dorsali triangulari, supra ventrales accurate exorienti ; anali Icevi, longd, altitudine 

 retrd cito decrescente ; utrdque plicis membranaceis, radiis longitudinaliter adhceren- 

 tibus, ins true td : squamis in lined laterali 46, in lined inter pinnas ventrales et dor- 

 salem transversa 17. 



B. 4 ; D. 1/10 ; A. 2/30 ; C. 19, &c. ; P. 13 ; V. 8. 

 Long. unc. 4. lin. 7. 

 Fokm.— Of a subrhomboidal form, the nape and back being much elevated, whence the profile falls 

 very obliquely and in nearly a straight line. Greatest depth nearly half the entire length, ex- 

 cluding caudal. Body very much compressed, the thickness being nearly three and a half 

 times in the depth. Head approaching to a laterally flattened cone, with the length and height 

 nearly equal. Snout very short; mouth but little cleft; when open, the lower jaw projecting 



• Swainson is of opinion that " more than double the number of species of Exoccetus really exist above those 

 that have been described." — Nat. Hist, of Fishes, vol. i. p. 299. 



