116 PROCEEDINGS OF THE NATIONAL MUSEUM ?ol. 84 



Remarks. — ^A single male was collected at Cottonwood Creek, 46 

 miles east of San Diego, Calif., on the road to El Centro, January 

 22, 1921, by Dr. O. F. Cook. 



DIACTIS FRONDIFERA, new species 



Figure 17, f 



Diagnosis. — The smaller size of the body, fewer crests on the first 

 segment, and the slender branches of the gonopods readily distin- 

 guish this species. 



Description. — Body 13 to 16 mm long, 1 to 1.2 mm wide, 44 to 51 

 segments. 



Eyes composed of 35 to 40 ocelli in 6 or 7 rows, counting downward 

 from the top of the head ; sense organ in front of rows 4 and 5, or 

 5 and 6, in contact with the triangular eye cluster. 



First segment with only 12 crests, occupying the posterior third of 

 the dorsal surface. 



Segments 2, 3, and 4 with the median pair of primary crests notably 

 divergent, and without an intervening pair of secondary crests, the 

 median pair of secondary crests first apparent on segment 5. 



Transition to the full niunber of dorsal crests occurs on segment 8. 



Primary crests rather strongly developed to within 4 or 5 segments 

 before the end of the body, their tops smooth and shining ; setae in- 

 serted at the posterior ends of the crests of moderate length ; sides of 

 crests and the surface between finely reticulate. Secondary crests 

 very thin, rather weakly elevated on the anterior segments, very faint 

 or entirely obsolete on the segments behind the middle of the body. 

 Poriferous keels and lateral crests as in soleata. 



Last segment smooth but for the six setiferous tubercles. 



Gonopods with the erect portion (fig. 17, /) with three slender 

 branches, two subapproximate at apex, the other shorter ; inner branch 

 longest, slightly curved, tapering gradually to a simple point ; outer 

 branch more strongly curved, terminating in two divergent prongs; 

 middle branch simple, inserted near the base of the outer branch, 

 projecting into the curve below its 2-pronged termination. 



Velutinous pads present on the under side of the last joint of the 

 male legs to well beyond the middle of the body. 



Anterior pair of legs on segments near the middle of the body 

 with distinct coxal lobes, directed forward. 



Type.—Mdl^, U.S.N.M. no. 1240. 



Remarks. — A male and female collected at Torrey Pines, near 

 La Jolla, Calif., November 1, 1925, by "Hardy." Several other 

 females subsequently collected in the same locality by Dr. O. F. Cook. 



