On Fresh-water Entomostraca. 57 



29. Ilyodromus substriatus, G. O. Sars. 



Ilyodromus substriatus, G. O. Sars, Fresh-water Entom. 

 N. Zeal., p. 45, PI. VI, figs. 3, a— c. 



Some few specimens of this form were found in the 

 samples sent from Mr. White! egge. It did not, however, 

 develop in my aquaria. 



Distribution. — New Zealand (G. O. Sars). 



30. Ilyodromus ellipticus, G. O. Sars, n. sp. 

 (PL 7, figs. 4, a— c). 



Specific Characters. — Shell much compressed, seen 

 laterally, regularly obloug or elliptical in form, both extre- 

 mities nearly equal and evenly rounded, dorsal margin but 

 very slightly convex, ventral almost straight: — seen from 

 above, narrow oblong, anterior extremity somewhat nar- 

 rower than the posterior. Valves nearly equal and having 

 the inner duplicatures very broad. Surface of shell very 

 faintly striated longitudinally, and clothed at each extremity 

 with scattered hairs, those of the posterior one being parti- 

 cularly long. Colour of shell transparent yellowish, each 

 extremity, but especially the anterior one, being tinged with 

 deep green. Caudal rami rather strong, and of the structure 

 characteristic of the genus. Length 1,18 mm. 



Remarks. — The present new species is somewhat allied 

 to I. substriatus, exhibiting a similar faint longitudinal stria- 

 tion, but it may be at once distinguished by the rather different 

 shape of the shell, which is more regularly oblong or ellip- 

 tical than in any of the other known species. 



Description of the female. 



The length of the shell in fully grown specimens does 

 not exceed 1,18 mm., and this form is accordingly somewhat 

 inferior in size to I. substriatus. 



