16 



SC0MBEES0C1D3:. 

 2. ZENARCHOPTERUS. 



Ilemirhamphis, -purt, Ciiv. & Yal.Hi^t. Poiss. xix. p. 1 (1846) ; Giinlli. Cat. Fish. 



vi. p. 259 (186G). 

 ZenarcJwptenis, Gill, Proc. Ac. Philad. 1863, p. 273 ; Bleek. Atlas lelitli. vi. p. 63 

 (1866). 

 Distinguished from the preceding by the rounded caudal fin, and the 

 modification of the anal fin in males in connexion with pairing habits, 

 the species of this genus being viviparous. Vertebra 31 + 13. 

 Coasts and fresh waters of the Indian and South Pacific Oceans. 



1. ZENARCHOPTERUS DTSPAR. 

 IJemirhamphus cUsjiar, Ciiv. & \^al. Hist. Poiss. xix. p. 58, pi. ccccclviii. (1816) ; 



Bleek. Nat. Tijdschr. Nederl. Lid. vi. 1854, p. 498 ; Giinth. Cat. Fish. vi. 



p. 274 (1866) ; Playf. Proc. Zool. Soc. 1867, p. 868 ; Klunz. Verh. zool.-bot. 



Ges. Wien, xx. 1870, p. 582 ; Peters, Mon. Berl. Ac. 1671, p. 32 ; Day, Fish. 



Ind. p. 517, pi. cxix. fig. 5 (1878). 

 Zenarclwptems dispar, Bleek. Nederl. Tijdschr. Dierk. iii. 1866, p. 164, and 



Atlas Iclith. vi. p. 63, pi. vii. fig. 4 (1866) ; Giinth. Fische Siidseo, p. 358 



(1909). 

 JTemirliamphis commersonii, part., Peters, Reise Mossamb. iv. p. 94 (1868). 



Depth of body 6 to 6^ times in total length, length of head 4 times. 

 Beak 1| to If times length of head, with membranous crest below ; 

 upper jaw as long as broad ; teeth minute, in villiform bands ; eye 

 better visible from below than from above, 4 times in length of head. 



FiK. 10. 



Zenarchoptenis dispar. 

 Type, after Ciivier and Valenciennes. 



Dorsal 11-12, two of the median rays thickened and more or less pro- 

 duced in the male. Anal 11-12, divided into two portions in the male, 

 the second portion beginning with the sixth ray, which, like the seventh, 

 is much thickened and produced, about f length of head. Pectoral 

 I length of head. Ventral inserted twice us far from prreoperculum 

 or posterior border of eye as from caudal. Caudal rounded, ujiper rays 



