ABDOMINAL MALACOPTF.RYGIANS. 181 



Tliey have ten branchial rays; their natatory bladder is very large, their 

 intestine straight and without coeca; the superior lobe of the caudal is the 

 shortest. They do not fly far: raising themselves to avoid the voracious 

 fishes, they soon fall down again, their wings merely acting as parachutes; 

 birds pursue them through the air, as fishes do through the water. They 

 are found in all the seas of hot and temperate climates. 



E.exiliens, Bl. 397. (The Mediterranean Flying Fish). Common 

 in the Mediterranean, and easily recognized by the length of its ven- 

 trals, placed posterior to the middle of the body ; the fin's of the young 

 are marked with black bands*. 



E. volitans, Bl. 398. (The common Flying Fish). Common in 

 the Atlantic Ocean, and has small ventrals placed anterior to the 

 middle of the body-j-. 



The American seas produce species with cirri, which are sometimes 

 simple %, sometimes double, and even ramous§. 



Next to the family of the Pikes we place a genus of fishes, which, 

 though differing but little from the former, has longer intestines and two 

 ca^ca. It will most probably give rise to a particular family. It is that of 



Mormyrus||, Lin. 



The Mormyri are fishes with a compressed, oblong, scaly body ; the tail 

 thin at its base, swelling out near the fin; the head covered by a naked, 

 thick skin, which envelopes the opercula and branchial rays, leaving no 

 opening in the latter but a vertical fissure — a circumstance which has led 

 some naturalists to assert that these fishes have no opercula, although they 

 are as perfect as in any other, and which has caused the number of their 

 branchial rays to be reduced to one, although they have five or six. The 

 opening of the mouth is small, and almost like that of the mammiferous 

 animal termed the Ant-Eater; its angles are formed by the maxillaries. 

 Slender teeth, emarginated at the ends, are planted in the intermaxillaries 

 and lower jaw, and there is a long band of small crowded teeth on the 

 under surface of the vomer, and on the tongue. The stomach is a round- 

 ed sac, followed by two caeca, and a long slender intestine almost always 



* Such was the little Carolina specimen described by Linnaeus, and, as I believe, 

 the Exocetus fasciatus, Lesueur, Ac. Nat. Sc. Philad. II, pi. iv, f. 2; the second Plra- 

 bebe of Pison, 61, is the volitans. 



t I see, by the drawings of Commerson, and by that of White, Bot. Bay, App., p. 

 266, as well as by the fishes lately received from our travellers, that both these forms 

 are found in the Pacific Ocean. 



N. B. The exiliens and the mesogaster, Bl. 399, closely resemble each other, and 

 it is not an easy matter to distinguish them by the descriptions and figures of travel- 

 lers. The eootans of Lin. seems to have been a volitans whose scales had fallen. 



X Exocelus comatus, Mitch, op. cit. I, pi. v, f. 1, probably the same as the Ex. ap- 

 pendiculatus, W. Wood, Ac. Nat. Sc. Phil. IV, xvii, 2. 



§ Exocetus fur cat us, Mitch, op. cit. I, f. 2, which I suspect is the same as Ex. Nut- 

 talii, Lesueur, Ac. Nat. Sc. Phil. II, iv, 1. 



|| Mormuros, the Greek name of a littoral fish variously coloured, probably the 

 Sp'irus mormi/rus, L. It was applied by Linnceus, not very happily, to fresh-water 

 fishes of an uniform hue. 



