22 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 82 



The abdomen of the female (pi. 12, fig. 3) is not bent. Of the four 

 sepnents, the first two are frequently imperfectly separated. The 

 furcal rami are about twice as long as broad and ciliate on the in- 

 ner border. The spermatophore is bent around the abdomen, as 

 shown in Plate 12, Figure 3. 



The second, third, and fifth segments of the male abdomen (pi. 

 12, fig. 4) are armed with projecting processes. The process of the 

 second segment is triangular, about one-half as long as the width 

 of the segment, and rather strongly concave on the distal border. 

 The process of the third segment is short and blunt and projects 

 from the dextral distal angle of the segment. The process of the 

 fifth segment is a small blunt pointed triangular hyaline plate on 

 the right side projecting forward. A beadlike row of serrulations 

 extends down the right side of the segment. 



The female antennae are stated by Lilljeborg and by Schacht to 

 reach the base of the furca; in the Massachusetts specimens they 

 reached the end of the furca. In the fifth feet of the female (pi. 

 12, fig. 5) the second basipod is about as long as its width and bears 

 near the outer distal angle a small spine or seta. The second basipod 

 and the two segments of the exopod are of about equal length. The 

 first segment of the exopod has a small spine at its outer distal 

 angle. The second segment has five terminal spines, or they may 

 be considered as three terminal and two lateral, one on each side. 



The male fifth foot (pi. 12, fig. 6) is much like that in E. lacustris 

 and E. nevadensis ; there is a distinct difference, however, in the 

 second segment of the exopod of the left foot ; this is slightly curved, 

 approximately of the same width throughout its length, blunt 

 pointed, armed with four spines on its external border, and ciliate on 

 the distal portion of the inner border. In some individuals the inner 

 border of this segment is sinuate, in others it is an unbroken curve 

 like the figure. Lilljeborg states that the second basipod of the 

 left fifth foot bears a large hook on its inner border and shows this 

 hook in his figure. Schacht (1898) also mentions this hook. The 

 hook was not found in any of the Massachusetts material, and 

 Schmeil (1898) stated that an examination of the original material 

 of Lilljeborg failed to show its presence. Schacht's statement that 

 he found the spine is evidently due to a misunderstanding. Schmeil 

 wrote of the " thorn " on the second hasipod of the i^iglit foot. This 

 would be the segment commonly spoken of as the first, which Schacht 

 refers to the second^ or first segment of the exopod. 



Lennth: According to Lilljeborg: Female, 2.9 mm, male, 1.1 mm; 

 according to Schacht : Female, 1.9 mm, male, 1.1 mm. The Massachu- 



