10 ATHERINID^: SILVERSIDES 



Another species from the same locality, called Mesogaster sphyr^- 

 NOIDES Ag-assiz, has also a produced snout, the premaxillary border being 

 straight, as in Atherina, not curved as in most American forms. 

 Mesogaster is a less elongate fish than Rhamphognathus, but it be- 

 longs to the general Atherina type. 



In a paper lately published, ^^ Dr. David Starr Jordan and J. Z. 

 Gilbert describe a new genus of fossil Atherinid.^ from the Monterey 

 Miocene deposits of Southern California. This genus, Zanteclites^ 

 (hubbsi) in its relatively few vertebrae, in the approximation of the 

 dorsal fins, and in the comparatively large and subfilamentous first dorsal, 

 suggests certain genera living in Australia and Madagascar, which, 

 as we have already indicated, may be among the more primitive forms 

 of this type. 



ZANTECLITES HUBBSI Jordan and J. Z. Gilbert (/. c. 39) 

 (Plate XI, Fig. 40) 



A little fish about four inches long, from the Puente diatomaceous 

 shales (Miocene) at Elmodena, Orange County, and at Shorb, Los 

 Angeles County, California, almost certainly belongs to the Atherinid.e. 

 It is referable, however, to neither the Atherinin.e nor the Atheri- 

 NOPSiN.^, the two groups now living in the Holarctic Realm, being more 

 primitive than any of the genera of either subfamily. Its primitive features 

 at once apparent are the relatively few vertebrae, the approximation of the 

 dorsal fins, and the relatively large first dorsal fin composed of spines 

 comparatively well spaced and fairly robust basally. Among living genera 

 Zanteclites bears the closest resemblance to Rheocles of Madagascar 

 and PsEUDOMUGiL of Australia and New Guinea, types which we regard 

 as relatively primitive among the Atherinid.e. From both of these 

 genera Zanteclites is sufficiently distinguished by the characters of the 

 dorsal fins. 



In the type-specimen of Zanteclites hubbsi the tail and trunk are 

 well preserved by a rather clear impression in the diatomaceous shale, 

 but the head has been crushed so that the cranium is seen in dorsolateral 

 aspect, while the opercles and shoulder girdle are below their normal 

 position. 



The top of the cranium resembles that of Atherina rather closely, 

 the wide supraorbital laminae being separated from the rest of' the frontal 

 by deep grooves widely divergent posteriorly. The length of the cranium 

 to the anterior end of the frontal bone appears to be contained four 



^^ Fossil Fishes of Southern California, bj' David Starr Jordan and James 

 Zaccheus Gilbert, Leland Stanford Jr. University Publications, 1919. 



