Mutation 



162 



The following are measurements of examples from the two horizons : 

 E. 1. b, carapace, length, 4 mm. ; width, 3 mm. ; depth, 2 mm. 



" 31 (( <( 3 ( 



E. 2c, right valve " 4J " " 3 " 



Mutation LIGATA, PI. XII., fig. 17. 



Jl 



1 



Can. Rec. Sci. Montreal, 1902, p. 451. 



Oval, cardinal curves long, anterior marginal curve straight, posterior 

 ornamented with a row of small tubercles; a similar row extends direct 

 from the lower end of the posterior cardinal curve toward the lower end 

 of the valve, near which it curves forward. Ocular tubercle obscure, it 

 appears to be represented by four small tubercles ; but the furrow is well 

 marked. 



Sculpture. The punctation is rather coarse, and there are anastomos- 

 ing ridges near the two ends of the valve, parallel to the margin. 



Size. Length 4 mm. ; width 3 mm. ; depth of two valves, 2 mm. 



Horizon and locality. Assise E. 3. e., Upper Etcheminian, at Dugald 

 brook, Escasonie, N.S. Rare. 



Genus 

 Bradoria. 



BRADORIA* 



Named for the Bras d'Or, a salt water lake occupying the interior of the island of 

 Cape Breton. 



"In the Protolenus Fauna are two species of Ostracoda which, for want 

 of other known relationship, were referred to the genus Primitia. It 

 would appear now that they are representatives of an ancient type of 

 crustaceans which has species in the Etcheminian Fauna. Though hav- 

 ing the general form of Primitia, Priinitiella and Aparchites, they do not 

 have the median pit, or sulcus of the first, the shallow median depression 

 of the second, or the smooth valve of the third. Their most marked 

 character is a prominence or tubercle at the front of the hing-line. From 

 the smoothness of the summit of this tubercle, and its advantageous posi- 

 tion for vision, it is supposed to be an ocular tubercle. Some of the species 

 have, close behind this tubercle, a short vertical furrow ; or the furrow may 

 pass around the tubercle. In the five species referred here the marginal 

 furrow is obscure, or in side-view along the lower margin, invisible. 



The known species are of nearly the same size about 3 to 4 ram. long 

 and the surface of the valves is distinctly pitted, tuberculated or wrinkled. 



*Nat. Hist. Soc. N. Brunswick, Bull. vol. iv., p. 204. 



