135 



being prolonged, even in cases where the lower jaw is produced 

 into a beak. Small or minute, sometimes tricuspid, teeth in 

 the jaws and sometimes present on palate and tongue. Second 

 and third upper pharyngeals dentigerous, the third pair strongly 

 enlarged, ankylosed or simply coalescent, forming one some- 

 what convex ovoid plate ; fourth upper pharyngeals absent ; 

 lower pharyngeal broad, triangular, with concave upper sur- 

 face; teeth on principal pharyngeal plates anteriorly villiform, 

 posteriorly incisors with transversely expanded horizontal edge, 

 the two types connected by teeth of intermediate form, many 

 of which are tricuspid. Parasphenoid with an inferior apophysis 

 in front of the upper pharyngeals. Pseudobranchiae hidden, 

 glandular. 



Key to the families of Exocoetoid e a. 



1. Intermaxillaries forming a flat, horizontal, triangular 

 expansion. Lower jaw generally produced into a long 



beak. Pectorals moderate') Hemirliamphidac p. 135. 



2. Intermaxillaries with a straight transverse anterior 

 border. Lower jaw never produced into a beak. 

 Pectorals long, generally excessively long, forming 



an organ of flight Exococtidae p. 173. 



^; I. Fam. Hemirhamphidae. 



Very elongate, slender, cylindrical or compressed. Maxil- 

 laries firmly united to intermaxillaries, which form a flat 

 horizontal, triangular expansion. The symphysis of the lower 

 jaw is always prolonged, sometimes only very little so, but 

 generally much, so that the lower jaw forms a long, slender 

 beak. Teeth rather small, often tricuspid, the part of the lower 

 jaw in front of the intermaxillaries generally without teeth. 

 No teeth on palate or on tongue. Pectorals inserted rather 

 high up, of moderate length, by exception very long. Dorsal long 

 or short, far back, beginning before, above or behind origin 

 of anal. Anal long or short, in the males of viviparous species 

 some of the rays are often modified. Ventrals moderate 



i) In the genus Eukptorhamphus^ not yet found in the indo-australian Archi- 

 pelago, the pectorals are long, but it is easily recognized as belonging to the 

 Hemirhamphidae by its long beak, formed by the lower jaw. 



