528 PROCEEDINGS OF THE NA TIONAL MUSEUM. voi- xxvi. 



I. TYLOSURUS SCHISMATORHYNCHUS (Bleeker). 

 DATSU. 



Belone granJl^ Rchlegel, Fauna Japonica, Poiss., 1846, p. 246, pi. ex, fig. 1; 

 Nagasaki; not of Lowe, 1839, a species from Madeira.— Bleeker, Nu-nwe 

 Nalez., Japan, 1857, p. 116.— Nystrom, Svensk. Vet. Akad. Handl., 1887, p. 44; 



MaM<mhelux gracUI>^ Bleeker, Ned. Tyds. Dierk., 1866, p. 111. 

 Belone srMsmatorJwichns Bleeker, Nat. Tydschr. Ned. Incl, I, 1850, p. 95 - 

 Bleeker, Verh. Gen., XXIV, 1866, p. 15.-Gdnther, Cat. Fish, VI, 1866, 

 p 239; Mozambique, Zanzibar.— Ishikawa, Prel. Cat., 1897, p. 18; Boshu. 

 Mashwembelus schmnatorhynchus Bleeker, Atlas Ichth. Ind. Belon., about 1870, 

 p. 49; Java, Ternate, Nagasaki. 

 Head from tip of upper jaw -ii to -li in length; depth equals post- 

 orl)ital part of head; dorsal 24: to 27; anal 25 to 27. 



Body very elongate and ratber strongly compressed, the sides vin-- 

 tical and parallel. Dorsal and anal outlines parallel from head to j 

 dorsal. Jaws very slender and long; upper jaw from anterior or])ital i 

 rim 2^ times longer than rest of head. Premaxillary toward base con- 

 stricted slightly and strengthened above Ijy a mass of bone along the 

 posterior fourth of the length, which ends in a point as ^'iewed from 

 above. Diameter of eve equals interorbital width and is contamed 

 2 to 2i in postorbital part of head. Top of head from above eyes 

 to occiput smooth with a translucent cartilage-like tissue. Nostril an 

 elongate, somewhat triangular pit containing a simple undivided 

 papilla. Head apparently naked except a patch of scales above 

 cheeks and another on top of head from eyes to base of mixillary. 



Pectoral equal to postorbital part of head or sometimes slightly 

 longer. Ventrals inserted nearer the anterior margin of the eye thau i 

 the base of the caudal bv a distance equal to a diameter of the eye, y 

 their length twice the diameter of the eye. Anal placed well mii 

 •advance of dorsal; the base of the sixth ray under the base of the first; 

 dorsal ray, the anterior part of anal strongly concave on its pes-, 

 terior margin. Distance of base of last anal ray from base of aux- 

 iliary caudal ravs li to li times the diameter of the eye; the last ray 

 reaches a little over half this distance. Distance from front of anal 

 to base of ventrals is contained 5 times in length from middle of eyo 

 to caudal base; the anal base exceeds this length by li times the 

 diameter of the eye. Dorsal scarcely so strongly concave behind 

 the anterior rays as anal; its longest rays are behind the middle 

 When tin is depressed the tip of eighth ray from the last reaches base 

 of last rav. Distance between base of last dorsal ray and l)ase o1 

 auxiliary \'audal rays equals diameter of eye; the depressed dorsi 

 reaches hve-sixths of this distance. Median caudal rays about half th«; 

 length of longest rays of lower caudal lobe, which is a little longe:; 

 than the upper. The lateral line is not at all produced as a keel oi 

 caudal peduncle. 



