prolonged, forming a beak. Both jaws with a band of conical 

 teeth and a series of moderate pointed widely-set teeth. Those 

 of the mandibles much smaller than those of maxillaries, which 

 are canines. Teeth on vomer present or absent. Dorsal and 

 anal almost opposite to each other; all the dorsal and anal 

 rays connected by a membrane. Caudal forked. Scales rather 

 small. Lateral line running low down, not forming a keel on 

 the caudal peduncle, which has sometimes a keel above the 



Fig. 46. Bclonc (Eitrycaulns) pcrsimllis Gthr. X V^- 

 Side- and upper view of end of tail to show tliat it is llatlened. 



lateral line. Gillopenings wide. Gillrakers present. Lower pha- 

 ryngeal triangular, second and third upper pharyngeals denti- 

 gerous; fourth usually distinct, dentigerous. 



Distribution: East Atlantic, Indie and Tropical Pacific. 



This genus can be provisionally devided into the 

 following two subgenera: 



A. \"omerine teeth piesent; tail compicsscd . . , Bcloiie s. str. '). 



B. Vomciinc teeth absent; tail depressed Eiirycatilits O'gxXhy -'). 



Key to the indo-australian species of 

 the subgenus Eur}' caul us: 



1. Eye l'/.2 — I-/;i in postoibital part of head, ecjual 



to interorbital space />. [E.) platyiira p. 118. 



2. Eye 1^/5 — 2 in postorbital part of head, a little 



more than interorbital space B. (E.) pcrsiniUts p. 118. 



i) Not represented in the Archipelago. 



2) We use here the name Eurycaulus^ although it was founded on a miscon- 

 ception. Ogh.ky (Proc. Royal Soc. Queensland XXI. 190S, p. 91) proposed to 

 subdivide the genus Tylosurus into three genera, and one of these genera he 

 called Eurycati/tis, with the type B. platyura\ but lastnamed species, having 

 gillrakers, is a Belone and not a Tylosurus^ which fact seems to have escaped 

 Oc.iLBV. The name Etiiycaiilus has presedence before Platybclone Fowler (Proc. 

 Acad. Nat. Sc. Philadelphia LXXI. 1919, p. 2). 



