168 



CALIFORNIA ACADEMY OF SCIENCES 



In tlieii* List of American Gobiidse, Eigenmann and Eigenmann (1888, 

 p. 52) distinguish the Atlantic and Pacific sjjecies of Philypnus {P. dormitor and 

 P. lateralis) by the size of the scales, the length of the head, and the number of anal 

 rays. In going over this ground later, Jordan and Evermann (1898, p. 2195) state: 

 " The only constant difference between this species \_P. lateralis] and Philypnus 

 dormitor seems to be the brighter coloration of lateralis." 



We have examined in this connection five specimens of P. dormitor, and thir- 

 teen specimens of P. lateralis. These bear out in the main the differences assigned 

 by Eigenmann. In P. dormitor, the head averages shorter, although the extreme 

 of variation includes some measurements of P. lateralis. The scales are smaller in 

 P. dormitor, although here again there is an overlapping in the formuhe. But in 

 P. dormitor the anal rays are constantly 10, while in P. lateralis they are constantly 11. 

 Below are data for individual specimens examined: 



p. LATERALIS. 



P. DORMITOR. 



We have not sufficient material to enable us to decide whether there are any 

 constant differences in coloration. The young of both species are marked by a 

 longitudinal band, interrupted, or narrowed at intervals by incursions of the ground 

 color. The only young specimen of P. dormitor in our possession shows three con- 

 spicuous cross-bars on the back: one under jwsterior portion of spinous dorsal, con- 

 tinued on the fin as a jet-black bar traversing its posterior and distal half; the 

 second, immediately behind the soft dorsal; the third, much narrower, just in advance 

 of the caudal fin. These become faint in adults, but we find traces of them in all our 

 specimens. Where traces of these bars exist in Pacific material before us, they are 

 very faint, even in brightly colored young, and do not involve the spinous dorsal. 



