ON SOME NEW OR IMPERFECTLY KNOWN 



SPECIES OF WEST AMERICAN 



CRUSTACEA. 



BY SAMUEL J. HOLMES. 



Plates XXXV-XXXVII. 



In the present paper, while a few new species have 

 been added, most attention has been given to the descrip- 

 tion of forms which have been very briefly characterized 

 or given wrong generic or specific names. As I have had 

 the opportunity of examining the types of several inad- 

 equately described species, it was thought best to redescribe 

 and figure these forms so that their identification might be 

 rendered a somewhat less hazardous undertaking. In a 

 few cases the recognition of the species from the original 

 description would be a practical impossibility; yet it is not 

 customary to consider a species indeterminate if its type be 

 extant, and there is danger, especially if the species is 

 assigned to a wrong genus or family, that it will be unsus- 

 pectingly redescribed under a new name. This source of 

 error at least will be largely eliminated by a fuller knowl- 

 edge of these forms. 



Most of the material upon which this paper is based was 

 obtained from the California Academy of Sciences through 

 the kindness of the former president of the Academy, 

 Professor William E. Ritter. 



[307] October 4, 1904. 



