WEST AMERICAN CRUSTACEA. 585 



Order PHYLL(3P0DA. 



Family APODID.E. 



Lepidurus Lemmoni sp. nov. 



Carapax oval in outline ; the sides are furnished with 

 numerous small teeth which begin near the rounded an- 

 tero- lateral angles and become longer, more slender and 

 more closely set towards the postero- lateral angles; the 

 dorsal crest of the carapax is furnished with a variable 

 number of unequally spaced spine -teeth which varied in 

 the specimens examined from ten to fifteen. The poste- 

 rior emargination of the carapax is furnished with from 

 five to seven teeth (counting the terminal ones), the 

 number of teeth on the two sides being often different in 

 the same individual. The postero-lateral angles are nearly 

 right angles. The eyes are usually reniform and their 

 anterior ends lie near together. The inter-ocular tubercle 

 is round, small, considerably elevated and located consid- 

 erably behind the posterior margins of the eyes. An- 

 tenna? short, simple, smooth. Second antennae absent. 

 Labrum nearly square but with rounded angles. The 

 maxilla? are deeply divided into an anterior lobe which is 

 cihated and a larger posterior lobe which is spinulous 

 along its inner edge. The first pair of legs are of mod- 

 erate length, none of the endites in the specimens exam- 

 ined reaching further back than the postero-lateral angles 

 of the carapax; the second endite reaches but little be- 

 yond the base of the third which is considerably longer 

 than the fourth; the fifth forms a short, pointed, ciliated 

 scale; gill triangular. 



In the second pair the second endite scarcely reaches 

 the base of the terminal ones, the third is about two-thirds 

 as long as the fourth ; the fifth is about as long as the 

 fourth, acutely pointed and finely pectinated on the inner 



