30 G. O. Sars. 



length of the ramus, apical seta very slender, almost reaching 

 to the tip of the claw, seta of dorsal edge scarcely ^ as long. 



Colour. — Shell highly pellucid, with a slight yellowish 

 tinge. 



Length of shell 1-84™™, height O-gO^"™, width 0-42™"». 



Remarks. — This is a ver}^ distinct and easily recogni- 

 zable form, which cannot properh^ be confounded with any 

 other known Ostracod, though in the sculpturing of the 

 shell it somewhat recalls certain species of the otherwise 

 very different genus Ilyodromus G. O. Sars. 



Occurrence and Habits. — Some few specimens of 

 this peculiar form, all of the female sex, developed in one 

 of my aquaria prepared with mud from Sumatra, and were 

 watched for some time. The specimens were not parti- 

 cularly agile, though at times they moved quite freely 

 through the water in the usual manner, a case never found 

 in any of the species of the genus Ilyodromus, all of which 

 are quite devoid of swimming powder. More frequently, 

 however, the specimens were seen kreeping slowty up the 

 walls of the aquarium or along the aquatic plants growing 

 in it. When disturbed, they started away in a most abrupt 

 manner, the body being propelled by an energetic exten.sion 

 of the powerful and very movable caudal rami. 



8. Notodroraas oculata, G. O. Sars. n. sp. 



(PI. IV, figs. 1, 1 a— c). 



Specific Characters. — Female. Shell moderateljT^ 



tumid, seen laterally, rounded oval in form, greatest height 



somewhat exceeding § of the length and occurring in the 



middle, dorsal margin considerably arched, ventral almost 



