248 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Measurements of Arctocephalus galapogoensis. 



Most of the skulls collected are those of immature 

 animals, but there are in the collection three adult skulls, 

 the measurements of which are given below. The adult 

 skulls are markedly different from the immature ones, the 

 greatest differences being the much narrower interorbitals, 

 the greater development of the mastoid processes, and the 

 presence of occipital and parietal crests. 



Measurements of the Skulls. 



No. 2480, old adult; sutures largely obsolete; occipital and parietal crests 

 high. 

 No. 2481, nearly adult; occipital crests low; sutures distinct. 

 No. 2482, same as no. 2481 in age. 



Family VESPERTILIONID^. 

 Lasiurus Gray. 



Lasiurus Gray, Zool. Misc. no. i, 1831, p. 38. 



Range. — ^Whole of the Nearctic, Neotropical, and Ha- 

 waiian Islands. Galapagos Archipelago (one peculiar 

 species). 



