﻿174 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lOo 



these authors. Kiefer included the first two names as synonyms of 

 E. serrulatus (Fischer) in his discussion on Cyclops (1939). Since 

 "the correct name for this species cannot now be determined, and it is 

 simply a matter of opinion" (Gurney, 1933, p. 99), and since Kiefer's 

 description of material from North India and Tibet at the other end 

 of the Tibetan Plateau has been used for comparison with this ma- 

 terial, it is more convenient to adopt his nomenclature. The specimens 

 from Yunnan, China, have been designated as a new subspecies for 

 the following reasons : 



(1) The ovisac in the female is smaller than in E. s. serrulatus^ its 

 posterior edge reaching the middle of the anal segment instead of the 

 end of the f ureal rami (cf . fig. 22, g^V). 



(2) The individual segments of the abdomen are longer than those 

 of the Tibetan species. 



(3) The anal segment is longer, in both male and female, than the 

 preanal segment, instead of shorter or equal to it. It is true that in 

 fixed material the degree of telescoping of the segments varies, de- 

 pending upon the degree of contraction of the abdominal muscles at 

 the moment of killing and fixing, but by examining the length of the 

 chitinous shell in transparent or semitransparent specimens this diffi- 

 culty can be overcome. In comparing the measurements so obtained, 

 the anal segment of the Yunnan material was found to be longer than 

 the preanal segment. 



(4) The second (or postgenital) segment in the male is longer than 

 the innermost spine of the sixth (or clasping) foot (see fig. 22, ;?*, h). 



(5) In the third and fourth pairs of swimming legs the skeletal 

 plate that joins the right leg with the left is armed with long hairs 

 on the ventral surface of the right and left sides and extending to 

 well beyond the caudal margin, but in the North Indian and Tibetan 

 specimens of E. s. serrulatus the free edge of this plate has very short 

 and evenly spaced hairs (cf. fig. 22, ^, n, o, and Kiefer, 1939, p. 137, 

 fig. 14/.). 



Adult female : Total length 1.05-1.23 mm., length of cephalothorax, 

 abdomen, and furca 116 : 80 : 21 ; maximum width at about the middle 

 of cephalothorax 0.306 that of total length. Genital segment as 

 long as the total lengths of the next two segments, anterior end of 

 genital segment expanded to about the same width as the last thoracic 

 segment, posterior portion greatly reduced; anal segment slightly 

 longer than preanal (9: 7-8), anal plate semilunar in outline with 

 smooth border, anal slit bordered with spiniform teeth increasing in 

 length posteriorly; posterior border with 10 to 12 strong spinelike 

 indentations on its dorsal and ventral sides. Outline of furcal rami 

 slightly curved on both lateral and medial sides, furcal length 5.5 to 

 5.7 times its width ; medial edge smooth, outer edge armed with saw- 



