AET. 18 SYNOPSIS OF CALAlSrOID CRUSTACEA — MARSH 19 



The antennae in the female (pi. 9, fig. 1) extend about to the 

 fourth abdominal segment. The fifth feet of the female (pi. 10, 

 fig. 4) are uniramose and 3-segmented, the first segment being the 

 second basipod and the other two the exopod. The first segment is 

 about as broad as long and bears a small spine at the outer distal 

 angle. The segments of the exopod are elongate and narrower than 

 the first. The second is about IV3 times the length of the first. The 

 first segment of the exopod has a spine at the outer distal angle. The 

 terminal segment has 6 spines, 4 terminals and 1 on each side; 3 of 

 the terminal spines are spinulose. In Plate 9, Figure 3, is shown the 

 endopod of the maxilliped, and in Figure 5 the second swimming foot. 



The right fifth foot of the male (pi. 9, fig. 4) is 2-segmented, con- 

 sisting of the second basipod and a 1-segmented exopod, broad at 

 the proximal end and diminishing to a blunt-pointed tip at the distal 

 end ; it is flexed upon the second basipod. The second basipod of 

 the left fifth foot has a seta at three-fourths the length of the outer 

 border ; the second segment of the exopod has a broad base and ter- 

 minates in a spine ; its inner border is concave and armed with long 

 hairs and it has on the outer border one to three spines. 



Occurrence. — E. lacustiis is found abundantly, especially in deep 

 cool waters, in Illinois, Indiana, Ohio, Minnesota, Wisconsin, Mich- 

 igan, and New York. It has been reported from Maine by Bishop 

 and Clarke, and I have seen specimens collected in Lake Sebago by 

 Doolittle. Willey (1920) reported it in Nova Scotia, Bigelow (1923) 

 in Lake Nij^igon, and Bajkov (1930) in Winnipeg, Winnipegosis, 

 and Atikameg. De Guerne and Richard (1889) stated that it was 

 found by Lilljeborg in a collection from East Portland, Oreg., and 

 Schacht (1898) repeats this location; it seems probable that this 

 identification was wrong and that Lilljeborg really had E. nevaden- 

 sis, as there is no other report of E. Jacustris in the Pacific coast 

 region. 



EPISCHURA NEVADENSIS Lilljeborg 



Plate 11, FiGtmES 2-7 : Plate 12, Figuke 1 



EpiscJiura nevadensis Lilljeborg, in de Guerne and Richard, 18S9, p. 93, pi. 2, 

 figs. 17, 24, pi. 3, fig. 21.— Hereick and Turner, 1895, p. 84, pi. 11, figs. 1, 

 6, 8. — GiESBRECHT and Schmeil, 1898, p. 183.— Schacht, 1898, p. 256. — 

 ToLLiNGEK, 1911, pp. 153, 154, fig. N*.— Marsh, 1918, p. 756, fig. 1174. 



Epischura nevadensis var. columbiae Forbes, 1893, p. 254, pi. 41, figs. 19-21. — 

 Herrick and Turner, 1895, p. 84, p. 11. figs. 4, 10. 



The abdomen of the female (pi. 11, fig. 2) is straight or nearly so ; 

 the first and second and the third and fourth segments are ordinarily 

 more or less confluent, so that the abdomen may appear to consist 

 of less than four segments. The spermatophores are straight or 

 slightly bent. 



