1 19 



D. 2.13; A. 2.17; P. I.I I ; V. 1.5 ; L. 1. about 1 80. 



Depressed, pentagonal in crosssection, the height 1.2 in the 

 breadth of the body. Height 25, 27 in length with caudal. 

 Head 2.8; 3.1 in length with caudal. Eye 1.6 — 2 in postorbital 

 part of head, a little more than interorbital space and 7.4 in 

 snout. Head flat above, with a broad shallow scaly median 

 groove. Supraorbital region striated. Operculum scaly. Maxil- 

 lary entirely hidden by praeorbital. Canines weak, short and 

 straight. Height of mandible below eye '/,; of greatest diameter 

 of eye. Tongue smooth. Pectorals a little longer than post- 

 orbital part of head, ventrals about 1.5 in pectorals. Base of 

 ventrals somewhat nearer to hindmargin of operculum than 

 to base of caudal. Origin of dorsal above third divided ray 

 of anal, separated by about 120 scales from occiput and by 

 10 — II scales from lateral line. Middle and posterior dorsal 

 and anal rays subequal in length, much shorter than the anterior 

 ones. Caudal peduncle very strongly depressed, with a sharp 

 lateral keel above the lateral line, its height more than twice 

 in its breadth. Caudal forked. Bluish-black above, silvery 

 below, fins yellowish. Length 500 mm. 



Habitat: Flores ! — Yap, Northwest Coast of Australia, 

 Sandwich Islands, Tonga Islands, Hawaian Islands. 



2. Tylosurus Cocco. 



(Cocco, Lett, in Giorn. Sc. Lett. Sicil. XLIL 1833, p. 18). 



Very elongate, body cylindrical or compressed. Intermaxil- 

 laries and mandibles prolonged, forming a beak. Both jaws 



Fig. 47. Tylosurus inclaiiolus (Blkr.) X Vs' 



with a band of small teeth and a series of more or less 

 developed canines. No teeth on vomer. Origin of dorsal some- 

 what or even considerably behind that of anal, all the dorsal 



