448 



CRUSTACEA. 



which is composed of eight segments. The eight pairs of thoracic 

 appendages may have an exactly similar shape, and possess two 

 separate and many-jointed rami. This form of thoracic appendage 

 is characteristic of the Schizopoda ; in Nebalia* the thoracic appen- 



FIG. 3?C. Nebalia Geoffroyi, strongly magnified, a, Female; 8, male; E, rostrum; O, 

 stalked eye ; M, crop ; D, intestine ; S, shell G, vas deferens. 



* Nebalia is best placed in a special group, Leptostraca, between the Entomos- 

 traca and Malacostraca. The palaeozoic fossil genera Hymenocaris, Peltocaris, 

 etc., would have to be placed in such a group. 



