586 CALIFORNIA ACADEMY OF SCIENCES. 



edge. The eleventh pair of legs in the female are sim- 

 ilar to those of L. glaci'alis. There are usually about 

 five of the terminal abdominal segments exposed and 

 nearly an equal number (sometimes less) which are de- 

 void of appendages on the ventral side. The number of 

 spines on the penultimate abdominal segment is never far 

 from twelve. On the upper side of the last segment is a 

 small, spinulous prominence in front of the base of each 

 stylet. The telson is rather long, oblong, somewhat wider 

 in the middle, and may be rounded, truncated (obliquely 

 so in some specimens), or, in some cases, bilobed ; 

 the margins are furnished with several minute spinules, 

 and there are, in most of the specimens, two spines in 

 the middle line at the base, but in one specimen there 

 were three spines at the base and a small one near the 

 middle. Except where the teeth are situated, there is no 

 median ridge or carina, as in L. Cousii. The caudal 

 stylets are minutely spinulous and are longer than the 

 body including the telson. 



Length, 28 mm. 



Color (in alcohol), greenish. 



Four females and one male loaned by Mr. Rivers. 



Collected at Honey Lake, by J. S. Lemmons. 



This is the fourth species of Lepidurus that has been 

 described from North America and the first member of 

 the Apodidaj reported from the Pacific Slope. When 

 Packard wrote his Monograph of N. Am. Phyllopods only 

 two species of that group were known ( JE stheria Calif or- 

 nica P. and E. Newcombii Baird), and I believe no spe- 

 cies has been added since. 



This species differs from L. Cousii Packard, to which 

 it is more nearly related than to any other American spe- 

 cies, in the spinous crest and sides of the carapax, in the 

 absence of a carina on the telson, in the greater length of 



