16 



SCOMBEESOCID,^^. 



2. ZENARCHOPTERUS. 



IIemirliamphus,\)i\vi., Ciiv. & Val.Hist. Poiss. xix. p. 1 (181G) ; Giintli. ('at. Fish. 



vi. p. 2b\) (1866). 

 Zenarchopterus, Gill, Proc. Ac. Philad. 18G3, p. 273 ; Bleek. Atlas Ichth. vi. p. 63 



(1866). 



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

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

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



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



1. ZENARCHOPTERUS DISPAR. 



Ilemirhain pints dixpai\ Cuv. & Val. Hist. Poiss. xix. p. 58, pi. ccccclviii. (187^6) ; 



Bleek. Nat. Tijdschr. Nederl. Ind. vi. 1854, p. 498 ; Gunth. 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. 1871, p. 32 ; Day, Fish. 



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

 Zenar chop ferns dispar, Bleek. Nederl. Tijdschr. Dierk. iii. 1866, p. 164, and 



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



(1909). 

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



Depth of body 6 to 6J 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. 



Fig. 10. 



ZenarcJioplerus dispar. 

 Type, after Cuvier 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 | length of head. Pectoral 

 f length of head. Ventral inserted twice as far fr(MTi praeoperculum 

 or posterior border of eye as from caudal, (,'audal roiinded, upper rays 



