54 PROCEEDINGS OF THE NATIONAL MUSEUM vol.86 



along the posterior margin a little way above each corner, the lovv'er 

 striae about a third as long as the dorsum, the upper ones shorter 

 and pointing obliquely upward; remainder of surface with minute 

 impressed lines forming a very inconspicuous network visible only 

 with rather high magnification. 



Segment 2 vritli a few fine striations low on the sides, the dorsum 

 smooth. Segment 3 also smooth but with the lateral striations ex- 

 tending above the line of the pores of the poriferous segments. 



Segments near the back end of the body with the pair of large, 

 inner, dorsal crests and the lateral carinae more elevated than on the 

 median segments and terminating in right-angled corners, but not 

 projecting beyond the posterior margin of the segments. Penulti- 

 mate segment a little shorter than the foregoing segment and Avith 

 the crests and carinae almost as strong. 



Gonopods as shown in figure 16, c. 



ODACHURUS, new genus 



Type. — OdachuniH petasatu.^, new species, from southern Califor- 

 nia. 



Diagnosis. — Closely related to Pharodere., with which it v/as found. 

 It differs in the flaring anterior corners and swollen surface of seg- 

 ment 1, which lacks lateral striations; the less prominent dorsal ridges 

 of the principal body segments, although on several segments pre- 

 ceding the penultimate the inner pair of ridges and the lateral ca- 

 linae are produced beyond the posterior margin; penultimate seg- 

 ment short and smooth. 



Descnption. — Body the same sha):)e and size as Phurodere. Head 

 with the labral and clypeal setae broken off but otherwise not differ- 

 ing notably from Pharodere. Cinathochilarium not dissected, but ap- 

 parently the mentum is in two parts. 



First segment with the anterior corners obtusely rounded and in- 

 conspicuously produced forward, very distinctly flaring outward 

 away from the sides of the body, when seen from in front or above, 

 jind forming the widest part of the segment; side margins very 

 oblique, with a raised marginal rim visible only in front as the 

 posterior half of the margin abruptly rolled under; posterior cor- 

 nel's quite sharp and slightly flaring away from the sides of tlie body 

 instead of clasping it as in other genera; dorsal surface inflated, 

 especially in front of the median part of the posterior margin which 

 is i^artly liidden from above; lateral .surface without striae. 



Segments 2, 3, and 4 forming a neck gradually narrowed to the 

 posterior margin of segment 4. which is onlv three-fourths the width 



