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PROCEEDINGS OF THE NATIONAL MUSEUM 



Table 2. — Measurements of five males and five females of Eucyclops serrulatus 



extensus 



Length 



900m- 

 865m- 

 847/i. 

 840m- 

 815m. 



Average - 



Furcal rami 



Length 



90.6m 

 73.5m 

 85m 



85m 

 78m 



V/idth 



18.5m 

 18.5m 

 18.5m 

 18.5m 

 18.5m 



L-W ratio 



4.9 

 4.2 

 4.6 



4.6 

 4.2 



Sixth leg 



44m 

 43m 

 44m 

 41m 

 39m 



42m 



Second 



abdominal 



segment 



59m 

 60m 

 60m 

 59m 



1,232m- 

 1,155m- 

 1,140m- 

 1,078m- 

 1,067m- 



Average. 



138 

 138 

 137 

 133 

 133 



24 



24 



24.1 



24 



24 



5.7 

 5.7 

 5.7 

 5.5 

 5.5 



5.62:1 



Specimens collected from Erh Hai in March are sexually mature; 

 the females carry either a pair of ovoidal spermatophores, which are 

 quite small, one-fifth the size of seminal receptacles, on the ventral 

 side against the opening of the receptaculum seminis (fig. 22, d), 

 or a pair of ovisacs on the dorsal side lateral to the abdomen, or both. 

 Very often females carrying empty shells of the ovisacs with their 

 contents discharged are observed among these eucyclopids, indicating 

 that spawning has just taken place. Specimens collected by the Yale 

 North India Expedition at Kashmir in April contain a number of 

 immature E. semdatus and some nauplii, while the mature females 

 have shed or are shedding the contents of their ovisacs. This may 

 indicate that this species breeds at nearly the same time in these 

 two places. 



Types. — The type series consists of the female holotype, male allo- 

 type, and male and female paratypes, U.S.N.M. Nos. 84541, 84539, and 

 84540, respectively. 



Genus TROPOCYCLOPS Kiefer 



TROPOCYCLOPS BREVIRAMUS, new species 



Figure 23 



This species is the smallest cyclopoid found in the lake. It is simi- 

 lar to Tropocy clops prasinus (S. Fischer) but is differentiated from 



