﻿198 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



of the female it is narrower and shorter. Distance from anterior 

 end of median eye to the foremost tip of the carapace 27.085 ±0.335 

 percent of total length. Abdomen obovate in outline, anterior end 

 broader, maximmn width 71.13 ±1.05 percent of length of abdomen, 

 being significantly wider than in the female. Anal sinus 37.76 ±1.15 

 percent of abdomen. Caudal rami basal (fig. 25, d), each in two sec- 

 tions as in the female. Secondary sexual characters on the swimming 

 legs as described by Thiele (1904), Tokioka (1936), and Meehean 

 (1940). But in addition to a slight spinous lobe on the lateral edge 

 of the thorax, between the second and third legs, directed from the 

 base of the third thoracic appendage anteriorly (see Meehean's fig. 

 32<?) , the dorsal surface of the last thoracic segment has a prominent 

 spinous lobe that projects anterolaterally over the opening of the 

 seminal receptacle on the third leg (fig. 25, j, k) . 



In the foregoing description no mention is made of the pigmented 

 spots, because an examination of the pigmentation — its color and 

 pattern — of this series of specimens indicates that it is not a useful 

 taxonomical character. Both AVilson (1904) and Cockerell (1926) 

 emphasized the linear arrangement of the pigmented spots on the 

 dorsum of their A. trilineatus {=A. japonicus). But among the 

 Erh Hai material pigmentation in the females varies from four 

 roughly linear rows of pigmented spots to no pigment at all. In the 

 case of the males, the young ones, like the young females, have pig- 

 mentation on the alae of the carapace, but among larger ones pig- 

 mentation is much less — down to a few brown spots on one side. Among 

 males larger than 3.5 mm. in length there is no pigmentation on the 

 dorsum at all. 



SUMMARY 



Two new diaptomid copepods, Tropodia'ptonms hebereroides and 

 Arctodiaptomus {Pararctodiaptomus) hsichowensis, found in Lake 

 Erh Hai, China, are described in this paper. Three cyclopoids occur 

 in this lake. Tropocyclops hreviramus is described as a new species 

 and Eticyclops semdatus extensus as a new subspecies. The uni- 

 versally occurring M eg acy clops mridis (Jurine) is compared with 

 forms found in North India and Tibet and with M. mridis acutulus 

 Kiefer from Java. 



A detailed examination of the literature on Argulus japonicus and 

 A. trilineatus is made. Wilson's A. trilineatus cannot be considered 

 valid but is a synonym of A. japonicus Thiele as indicated by Meehean. 

 Wilson's japonicus (1944), if not based on errors of observation, must 

 refer to a different species, but no specimens in agreement with the 

 description are known. A statistical analysis of A. japonicus from 

 Erh Hai is made and, based upon it, a supplementary description of 



