NO. 5 MYERS AND WADE: ATHERINID FISHES 127 



Head and body compressed, especially ventrally. Head truncate pos- 

 teriorly. Preopercular angle ending in a small, fiat, blunt, closely ap- 

 pressed "spine." Interorbital convex. Eye moderate, equal to or slightly 

 less than shortest distance between orbit and angle of preopercle. 



{Nectarges, from '^■qKrrj'i, ov, 6, a swimmer, and 'Apyrjs, ijro'i, 6, bright 

 or silvery.) 



This genus is closely allied to Eurystole and, with Eurystole, keys 

 down to that genus in Jordan and Hubbs' 1919 analysis of Atherinid 

 genera — as would be expected, since their account was apparently based 

 on Nectarges nepenthe. Other than in the fundamental and trenchant 

 characters utilized in our key, Nectarges differs from Eurystole in the 

 more compressed body and the decidedly narrower cranium, in addition 

 to a number of lesser characteristics. 



It is possible that the remarkable Notocheirus hubbsi Clark (1937, 

 p. 89, fig., Valparaiso, Chile) is related to Nectarges and Eurystole. Ex- 

 cepting for the inordinately high pectoral and the absence of the first 

 dorsal fin, Notocheirus shows considerable resemblance to Nectarges 

 nesioteSj but almost no characters that would enable one to determine its 

 phylogenetic relationships to other Atherinid genera are given in the orig- 

 inal description, nor was any attempt made to suggest such relationships. 

 Through the courtesy of Mr. Clark, we had a brief opportunity to exam- 

 ine the holotype of A^. hubbsi and the single, stained and cleared paratype 

 in the California Academy. However, our time was so short and the con- 

 dition of the two known specimens so poor that we were unable to form 

 an opinion. It is probable that Notocheirus is either a very specialized rel- 

 ative of the genus I so (known from Japan, Australia, and South Africa) 

 or a terminal, highly modified development of the Eurystole-Nectarges 

 line. 



Returning to Nectarges, it seems clear that this genus and Eurystole 

 form a very distinctive and rather isolated group of the subfamily Atherin- 

 opsinae, within which no genus approaches them closely enough to make 

 direct relationship discernible. The combination of a deep, short, "trun- 

 cated" head and a wide lateral band is duplicated elsewhere only in Iso 

 (and Notocheirus), but Jordan and Hubbs place Iso in the subfamily 

 Atherininae, and it seems probable that these characters are more recent 

 and specialized than fundamental. The deep, short head of Melanorhinus 

 (concerning which genus see below) does not seem to indicate relation- 

 ship to the present group. Upon purely geographical grounds, one might 

 suspect Eurystole and Nectarges to have arisen from Melaniris { = Thy- 



