ZooL.— Vol. III.] HOLMES— WEST AMERICAN CRUSTACEA. 321 



cles on the telson were all males, while all of the twelve 

 remaining specimens in which the telson was smooth above 

 were females. Not the smallest difference could be detected 

 between the two series of specimens aside from these two 

 features which are doubtless dependent upon difference of 

 sex. 



This description and the figures accompanying it are 

 taken from specimens from the California Academy of 

 Sciences (No. 2601) which are most probably the types 

 described by Mr. Lockington. The bottle of specimens is 

 labeled '■^ Idotea Harfordi, Santa Rosa Is. W. G. W. 

 Harford." Mr. Lockington, for some reason, came to 

 regard his ^ga Harfordi as an Idoiea as shown by Miers' 

 statement that '* ih^ ^ga Harfordi of Lockington is desig- 

 nated Idotea Harfordi in a MS. note of the author. . . . 

 Specimens, however, are in the British Museum from Santa 

 Rosa Island, received from Mr. Lockington, which do not 

 belong to any genus of IdoteidcB, but to Cirolana, or a 

 closely allied type" (Jour. Linnean Soc. v. 16, p. 19, 

 1883). The specimens sent to the British Museum and 

 those here described are probably parts of the same lot. 



Family ASELLID^. 



Asellus tomalensis Harford. 



Plate XXXVII, Figs. 39-42. 



Asellus tomalensis Harford, Proc. Calif. Acad. Sci. v. 7, p. 54, 1877. Rich- 

 ardson, Proc. U. S. Nat. Mus. v. 7, p. 856, 1899. 



Body narrow in front, widening gradually posteriorly. Thoracic seg- 

 ments of about equal length, with the sides rounded, the first segment slightly 

 longer than the others and having a notch in the lateral margins; anterior 

 segments concave in front, posterior ones concave behind. 



Head broader than long, widest a short distance behind the eyes; frontal 

 margin concave, antero-lateral angles rounded. Eyes rather small. First 

 antennas about reaching the middle of the last joint of the peduncle of the 

 second pair, the first joint oblong, flattened, outer margin concave, the 

 inner convex, second joint subcylindrical, longer than the first but about half 

 as wide; third joint narrower than the second and about | as long; flagellum 

 nearly as long as the peduncle and composed of 10 joints. Second antennae 



