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. > 
DY TAN Toe. 1G. ce.c bs 135 VC; 
Length 12 inches 8 lines. 
Cotour.—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 FE. exsiliens of 
Bloch, but as I am not aware that the species of Exocatus 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.* 
Famity.—SALMONID. 
1. TeTRAGONOPTERUS ABRAMIS. Jen. 
Prate XXIII. fig. 1. 
T. corpore subrhomboideo, compressissimo, altitudine fere dimidium longitudinis, pin- 
né caudali exclusd, equante: osse maxillari angusto, retrorsum arcuato : pinnd 
dorsali triangu/art, supra ventrales accurate exorienti ; anali levi, longa, altitudine 
retro cito decrescente ; utrdque plicis membranacets, radiis longitudinaliter adheren- 
tibus, instructd : squamis in lined laterali 46, in lined inter pinnas ventrales et dor- 
salem transversd 17. 
Bo4e Ds lO VA 2/30! 3Co 19. Scene 135) V8. 
Lone. unc. 4. lin. 7. 
Form.—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 Hxocetus really exist above those 
that have been described.” —WNat. Hist. of Fishes, vol. 1. p. 299. 
