﻿FRESH-WATER OSTRACODA FROM BRAZIL — TRESSLER 81 



the length; highest sHghtly anterior to the middle. Dorsal margin 

 arched, with an indistinct angle at the highest point. Both ends 

 broadly rounded, the anterior extremity slightly more so than the 

 posterior. Ventral margin convex and slightly sinuated. Surface 

 of valves smooth, with a few fine hairs and with irregular polygonal 

 markings here and there on the valves. Second antennae with nata- 

 tory setae, which reach slightly beyond the tips of the terminal claws. 

 First leg with a long, well-developed terminal claw, a distinctly 

 divided next-to-last segment, and heavy bristles along the inner 

 margin. Second leg with a slightly bent terminal beak and a short, 

 reflexed seta. Bristles along the inner margin not very well developed. 

 Furca long and slender. Dorsal margin with five groups of fine hairs. 

 Dorsal seta short and removed from the base of the subterminal claw 

 by the thickness of the base of the claw. Terminal seta lacking a 

 little of being half the length of the terminal claw. Subterminal 

 claw about two-thirds the length of the terminal claw. Both claws 

 finely haired. Length 1.08 mm.; height 0.63 mm. 



Male: Unknown. 



Holotype.—'U.S.NM. No. 83006. 



Type locality. — Eight specimens were collected by Dr. Kleerekoper 

 in a lakelet in the state of Rio de Janeiro (October). 



Genus CYPRETTA Vavra 



Cypreiia VXvra, Mitt. Mus. Hamburg, vol. 12, p. 6, 1895. — G. W. Mullbr, 

 Abh. Senckenb. Ges., vol. 21, p. 283, 1898.— Furtos, Amer. Midi. Nat., 

 vol. 17, p. 493, 1936. 



Very small forms, never longer than 1 mm. Very tumid when 

 viewed from above and high and broadly arched when viewed from 

 the side. Anterior margin of each valve with a row of prominent, 

 radiating striata. Natatory setae of second antennae well developed 

 as a rule. Furcal rami poorly developed with the claws reduced to 

 setalilce structures. Terminal and dorsal setae often lacking. 



CYPttETTA COSTATA G. W. Mullcr 



Figure 14, z 



Cypretta costata, G. W. Mullbr, Abh. Senckenb. Ges., vol. 21, p. 283, 1898. 



Specific characters. — Female: Shell very high; height equal to almost 

 five-sixths the length and highest in the middle. Dorsal margin highly 

 arched, wath a trace of a blunt angle at the highest point. Both 

 extremities broadly rounded. Anterior margin of valves with a series 

 of very prominent radiating septa. Viewed from above, very tumid, 

 the breadth equaling four-fifths of the length. Natatory setae of 

 second antennae extend beyond the tips of the terminal claws. Furcal 

 ramae with terminal setae missing. Ramus slightly curved. Ter- 



