64 PROCEEDI^^GS OF THE NATIONAL MUSEUM tol. 86 



two short rudimentary striae sometimes present in the angle; back 

 margin straight througliout its length. Anterior segments shown 

 in lateral view in figure 20, d. 



Segments 2, 3, and 4 flat, without transverse constrictions; sides 

 slightly narrowing backward, the posterior margin of segment 4 

 about ten-thirteenths as wide as the widest part of segment 1 ; lateral 

 striae reaching higher on segments 4 and 5 than on any other 

 segment. 



From segment 5 to the antepenultimate segment strong transverse 

 constrictions are present; anterior subsegments moderately convex, 

 with coarse reticulations in front sometimes showing through the 

 semitransparent posterior subsegments, and with shallow rectangular 

 channels behind, twice as long as broad and separated by fine, raised, 

 and very inconspicuously beaded lines. Posterior subsegments with 

 fine median sulcus, more impressed on the back half ; surface shining 

 and with many tiny impressed longitudinal lines except on the 

 extremely faint lateral swelling where a considerable area around 

 the pore is dull and conspicuously reticulated. Posterior view of a 

 segment from near the middle of the body is shown in figure 20, e. 

 Pores beginning on segment 5. borne on the anterior slope of the 

 faint swelling, the pore minute, without an encircling rim. Penulti- 

 mate segment much shorter and less convex than the preceding 

 segment, the anterior subsegment exposed only on the sides. 



Last segment as long as the two preceding segments together; the 

 apex rather narrowly rounded and exceeded by the anal valves, with 

 four apical setae but none on the side margins. 



Anal valves moderately inflated, meeting rather abruptly in a 

 narrow, shallow groove. Preanal scale less than half as long as 

 broad; processes relatively large. 



Gonopods as shown in figure 20, /. 



First nuile legs reduced in size but with full}' developed claws. 

 Other pregenital legs without special modifications. 



Genital segments prominent below ; the back margins of the broad, 

 overlapping pleurae of segment G continuous with the back margin 

 elsewhere, not produced caudad ; opening in segment 7 biarcuate 

 behind, the surrounding margin strongly raised. 



LEIODERE DASYURA, new species 

 FlOtTRE 21 ; Pl_\TE 2, FlOl'liE 2 



Several specimens, including the male type (U.S.N.M. no. 1315), 

 collected at Tajiguas, Calif., January 1, 1928, by Dr. O. F. Cook, who 

 also collected a male east of San Lucas, Calif., December 20, 1930 



Description. — Body slender, 15 to 18 mm long and 0.8 to 1 mm 

 broad; females a little stouter than the males; body cylindric, com- 



