394 CALIFORNIA ACADEMY OF SCIENCES. 



but is distinguished by the more declivous forehead and 

 the shape of the rostro-f rental fontanelle. 



"A single specimen was forwarded to the Smithsonian 

 Institution by S. E. Hubbard, Esq., of San Francisco, 

 Cal." (Gill.) 



21. Manta birostris (Walbaum). 



Said to be frequently seen in the open sea about Ma- 

 zatlan; not obtained by us. 



Family SILURID^. 



22. Felichthys pinnimaculatus (Steindachner). 

 Occasionally taken in the estuary. Recorded by Gil- 

 bert from Mazatlan and Panama, by Steindachner from 

 Altata, Costa Rica and Panama. Two specimens ob- 

 tained by us. 



23. Felichthys panamensis (Gill). 



Not rare in the estuary, reaching a considerable size. 

 Obtained by Gilbert at Mazatlan, Libertad, Punta Arenas; 

 by Gill and Giinther at Panama; and by Steindachner at 

 Magdalena Bay, Altata and Panama. One specimen ob- 

 tained by us. 



24. Galeichthys peruvianus Liitken. Panama. 

 Recorded by Steindachner from Altata; not seen by 



us, and taken by Dr. Gilbert only at Panama; apparently 

 not common. 



The so-called genus Galeichthys is distinguished from 

 Hexanematichthys only by having the bones of the head 

 covered by skin. In several species of other genera 

 (notably -platy^ogon, dasycefhalas, gilherti), the skin on 

 the head is thickened in females, obscuring the outline 

 and granulation of many of the bones. It may be that 

 the species called Galeichthys represent only the extreme 



