114 



BULLETIN" 15 8, UNITED STATES NATIONAL MUSEUM 



and the form of the fifth legs, especially in the female, are the chief 

 distinctive characters. 



EURYTEMORA LACUSTRIS (Poppe) 



Figure 70 



Temorella lacustris Poppk, Zeitschr. Wiss. Zool., vol. 45, p. 278, pi. 15, figs. 10-13, 



1887. 

 Eurytemora lacustris Sars, Crustacea of Norway, vol. 4, p. 103, pi. 70, 1902. 



Occwrrence. — Both sexes found in abundance in surface tows in 

 Quisset Pond, Falmouth; Poucha Pond and Pond No. 1, Chappa- 

 quiddick Island ; Oyster Pond, Falmouth and Gosnold Upper Pond, 

 Cuttyhunk Island ; found in small numbers in Farm Pond, Marthas 

 Vineyard; John Pond, Mashpee; Oak Bluffs Pond, Marthas Vine- 

 yard. 



Distribution. — Sweden (Lilljeborg) ; Germany (Poppe) ; Finland 

 (Nordquist) ; Ladoga (Nordquist) ; Norway (Sars). 



FiGUBE 76.- 



-Eurytemora lacustris: a, Male, fifth legs; b, female, fifth legs; 

 c, female, abdomen and caudal rami 



Color. — Both sexes are highly transparent and practically color- 

 less, and hence very difficult to detect in a dish of water. 

 , Female. — Head separated from first segment, with a slight cervical 

 depression on the dorsal surface ; fifth segment with rounded corners ; 

 genital segment slightly dilated through the center, its lateral mar- 

 gins sparsely setose; anal segment and caudal rami without dorsal 

 spines; second (basipod) segment of fifth legs wider than long, with 

 an outer seta; third segment very short, no longer than wide, with 

 two small outer, and a slender inner spine ; inner apical spine of end 

 segment four times as long as outer. Total length, 1.2-1.4 mm. 



