70 G. 0. Sårs 



37. Chydoriis eurynotus, n. sp. 



(PI. XI, figs. 3, a-c). 



Specific Characters. — Female. Carapace 

 very tumid in its dorsal part, somewhat more compressed 

 below; seen laterally, of the usual rounded form, with the 

 hind extremity narrowly truncated, upper corner more distinct 

 than lower, both dorsal and ventral margins boldly curved. 

 Head very broad, and rather mobile, admitting of being 

 closely applied to the anterior edges of the valves, rostral 

 projection considerably produced, acumiûate, slightly recurved, 

 edges of fornix evenly curved. Surface of shell perfectly 

 smooth, only marked with fine punctures; inner ciliated 

 duplicatures of valves at an unusual distance from the mar- 

 gin and somewhat flexuous, posterior edges with double 

 contour. Ocellus much smaller than the eye. Lip-plate ob- 

 tuse at the tip. Caudal part rather produced, and of almost 

 uniform width throughout, upper basal corner considerably 

 thickened, supra-anal projection well defined, lower corner 

 rounded off, marginal denticles rather small, about 12 in 

 each row, caudal claws with a single basal spinule, distal 

 part finely denticulate, caudal setæ unusually strong and 

 somewhat flexuous. Male, as usual, much smaller than 

 female, and less regularly rounded; caudal part somewhat 

 lamellarly expanded distally, and obliquely truncated at the 

 end, dorsal edge scarcely incised. Colour bright yellow. 

 Length of adult female 0.45 mm., of male 0.32 mm. 



Remarks. — This form somewhat resembles the 

 European species, C. ovalis Kurz, and like it does not ex- 

 hibit any distinct sculpturing of the shell. It is, however, 

 easily distinguished by the different form of the lip-plate 

 and of the caudal part in both sexes. 



