Ostracoda 7 



Remarks. — The above described form is unquestionably referable to the 

 genus Cypricercus, as defined by the present author in his most recent publica- 

 tion (Account of the Crustacea of Norway, Vol. IX, Bergen, 1925, p. 117). It 

 is, however, well distinguished from any of the other known species by the very 

 pronouncedly scabrous surface of the shell, this character having indeed given 

 rise to the specific name proposed. In the structure of the several appendages 

 I have not found any essential difference from that in the other species. Yet, 

 for comparison, figures of some of the Hmbs have been given on the accompany- 

 ing plate. 



Occurrence. — Three female specimens only of this easily recognizable 

 form have come to my notice. They were found in two samples taken by Mr. 

 Fr. Johansen at the two following localities : — 



Rideau canal, Ottawa, Ont., June 9, 1918 (1 specimen). 



Pools at Billings bridge, Ottawa, Ont., June 16, 1923 (2 specimens). 



7. Heterocypris incongruens (Ramdohr) 



Occurrence. — This seems to be the commonest ostracod occurring in 

 Canada, as a rather considerable number of specimens have been collected by 

 Mr. F. Johansen from several places. The localities are as follows: — 



Pools at Aylmer road (near Deschenes), Que., May 15, 1921 (numerous 

 specimens) . 



Pond on the pasture at Graham Bay station, Britannia, Ottawa, Ont., 

 May 28, 1922 (several specimens) . 



Rock-pools at Cape Gaspe, Que., Aug. 12, 1922 (numerous young specimens 

 and detached valves). 



Shallow pond at Chelsea road. Que., near Ottawa, May 2, 1922 (several 

 specimens). 



Pools along the road (grassy clay at the, bottom). Port au Port, west coast 

 of Newfoundland, September 2, 1922 (numerous specimens). 



Genus Prionocypris Bray and Norman 

 8. Prionocypris canadensisj n. sp. 

 Plate III, figs. 8-16. 



Specific Character. — Female. Shell somewhat compressed, see laterally 

 (fig. 8) oblong trigonal in shape, greatest height in front of the middle 

 and not fully attaining half the length, dorsal margin gibbously arched at some 

 distance behind the ocular region, and sloping nearly at a straight course to 

 each extremity, ventral margin distinctly sinuated in the middle, anterior 

 extremity broadly rounded, posterior much narrower and obhquely produced, 

 terminating below in an obtuse corner; see dorsally (fig. 9), narrow oblong in 

 outline, with the greatest width about equal to two-fifths of the length, both 

 extremities pointed and nearly equal. Valves subequal and rather thin, semi- 

 pellucid, with the edges unarmed, surface smooth and only sparingly hairy. 

 Anterior antennae (fig. 10) with the terminal part scarcely longer than the 

 basal one, first joint about the length of the two succeeding ones combined, 

 setae rather elongated. Posterior antennae (fig. 11) with the first joint of the 

 terminal part moderately dilated and sUghtly longer than the other two com- 

 bined; natatory setae reduced to very small rudiments (see fig. 12). Oral 

 parts and legs (figs. 13-15) of quite normal structure. Caudal rami (fig. 16) 

 rather powerfully developed and perfectly straight, hnear in shape; distal 

 apical claw scarcely attaining half the length of the ramus, dorsal seta small 

 and attached near the apex. 



Colour not yet ascertained. 



Length of adult female 1-40 mm. 



Male unknown. 



