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



jusqu'au bout notre epreuve; nous avons cependant con- 

 duit leur education jusqu'a la troisieme mue: mais passe 

 cette limite, soit que I'etat de captivite dans lequel nous les 

 tenions leur fut contraire, soit que le genre de nourriture 

 que nous leur donnions ne leur convint pas, ils finissaient 

 par mourir successivement sans avoir atteint I'age adulte." 

 Since Sjyhceroma and Cymodoce closely resemble each other 

 in form and habit and are often found in the same local- 

 ities, and since Sphseromas carrying eggs are often met 

 with, while Cymodoce has never been observed to bear ova, 

 Hesse includes both forms under the latter genus. Dr. 

 StebbingS who takes exception to Hesse's conclusion, re- 

 marks that " as between British species assigned to the two 

 genera, there is no resemblance in color worth speaking of, 

 and no community of residence, except that Cymodoce is 

 occasionally and very rarely found on some of the shores 

 that also yield Sfhccrom^a. In S^h<Bro7na quadridentatuTn 

 Say, Mr. Harger has ascertained that neither sex is a 

 Cym.odoce. ... I can, however, myself testify that 

 Sphceroma rugicauda Leach need not have recourse to a 

 Cytnodoce for a male form." Whatever validity there may 

 be in Hesse's conclusion regarding the specific identity of 

 the forms studied by him, his general conclusion that 

 Sphceroma represents the female form of Cymodoce cer- 

 tainly cannot be maintained. On the west coast of the 

 United States SphcBroma is represented by several species. 

 I have observed thousands of specimens of this genus in 

 various localities from Oregon to Lower California, and 

 have never seen a single Cymodoce associated with them. 

 In fact, up to this time, there has been no species of 

 Cymodoce described from the Pacific coast of North 

 America. Moreover, by an examination of the sexual 

 organs of three west American species, Sphceroma oregonen- 

 sis Dana, Sphceroma rhomburum Richardson, and SphcBroma 

 pentodo7i Richardson, and of Sphceroma serratum (Fabr.) 

 from the Bay of Naples, I have ascertained that both males 



1 A History of Crustacea, N. Y. 1883. 



