154 PHYSOSTOMl. 



Genus III. — ExocffiTUS, Artedi. 



Gijpsilurus, Swainson: Halocypselus, Weinland : Parexocoetus, Bleeker. 



Bod)/ moderately ohlong. Qill-openings very wide. Jaius short, the premaxillaries 

 and niaxillaries separate : mandible in some species with a tubercular prolongation. 

 Barbels present or absent. Teeth, when present, minute and rudimentary. Pectoral 

 elongated, used as an organ for flying : the dorsal fin may lie much or only 

 moderately elevated : ventrals long, short, or of moderate length. Air-bladder large. 

 Pyloric appendages absent. 



Bleeker institnted tlie genus, Parexocoetus, for some species as E. m,ento. Cut. 

 and Val., destitute of barbels but wifh a short tubular prolongation of the lower 

 jaw, as if an aborted attempt at elongation as seen in Hemiramphus. Barbels 

 and transYerse bands may be symptomatic of tbe immaturity of the specimen. 

 Liitken draws attention to tbe following important generic characters, which 

 have been overlooked. There are those in which the second ray of the pectoral 

 fin is entire : others in which it is deeply cleft, and when the second ray is thus 

 cleft the third is always the longest (Vid. Medd. 1876, pp. 389-408, pi. x). 



Geographical distribution. — Seas of tropical and semi-tropical regions, extending 

 into more temperate zones. 



1. ExoccBtua volitans, Plate CXXVIII. 



Hirundo, Salv. fol. 185, pi. Ixvii. Exocoetus, no. 1, Artedi, Genera, p. 8, and 

 Spec. p. 35. Hirondelle de Mer, Duhamel, Peches, ii, p. 480, pi. xxii, f . 2. 



Exocoetus volitans, Linn. Amoen. Acad, i, p. 320, and Syst. Nat. i, p. 520 ; 

 Bonnaterre, Ency. Ich. p. 181, pi. Ixxiii, t. 306 ; Gmel. Linn. p. 1399 ; Yarrell, 

 Brit. Pish. (ed. 1) i, p. 398, c. fig. (ed. 2) i, p. 453 (ed. 3) i, p. 479 ; Cuv. and 

 Val. xix, p. 83, pi. 559 ; Swainson, Fish, ii, p. 296 ; Guichen. Exp. Alger, p. 26 ; 

 White, Catal. p. 73 ; Gunther, Catal. vi, p. 293 ; Malm, Fauna, p. 555 ; Collett, 

 Norges Fiske, p. 177 ; Canestrini, Fauna Ital. Peso. p. 132 ; Liitken, Contr. diag. 

 Poiss. volants, Joum. Zool. vi, 1877, p. 118 ; Giglioli, Peso. Ital. p. 43 ; Moreau, 

 Poiss. France, iii, p. 481. 



Exocoetus exsiliens, Bloch, t. xxxvii ; Bonap. Catal. no. 724. 



Cheater Flying Fish, Couch, Fish. Brit. Isles, iv, p. 128, pi. ccvii. 



B. x-xi, D. 11-13, P. 15-17, V. 6, A. 9, C. 19, L.l. 63, Vert. 31/14. 



Length of head 5i to 6f , of caudal fin 4, height of body 6 to 7i in the total 

 length. Eyes — diameter of each 3 to 3i in the length of the head, nearly 1 

 diameter from the end of the snout, and IJ diameters apart. The form of the 

 body is liable to modifications, in some having a convex superior profile or it may 

 be broad and flattened almost as far as the origin of the dorsal fin. Upper 

 surface of the head flattened. Snout obtuse : cleft shallow : the lower jaw 

 slightly longer than the upper : the superior maxilla hidden by the preorbital 

 when the mouth is closed. Teeth in jaws minute. Fins — the dorsal commences 

 on a line above the vent, its first ray simple : the pectoral reaches to the ba.se of the 

 caudal fin, its second ray divided, its third the longest. The ventrals are inserted 

 a little posterior to the middle of the distance between the end of the snout and the 

 base of the caudal fin, they are elongated, being more than ^ longer than the head. 

 Anal commences beneath the posterior dorsal rays. Caudal lobed, lower lobe much 

 the longer, but the proportions vary in individuals. Colours — bluish-gray along the 

 back, silvery on the sides and beneath. Dorsal fin grayish-white, caudal brown. 

 Pectoral gray with a light outer edge. Ventral and anal whitish or bluish. 



Names. — Flying-fish. Hirondelle de mer, ou Hareng volant, French. 



