PHYLLOPOD CRDSTACEA OF JAPAN. 139 



The eye is large, situated close to the aiiterioL- bordei- of the head. 

 The crystalline lenses are rather large and of an oval shape. They are 

 not very numerous, 7 to 8 being seen projecting at the edges of the 

 black pigment. The ocellus is very distinctly to be seen, and is placed 

 nearer to the posterior border of the head than to the eye. 



The first pair of antenna is situated on a small rounded prominence 

 just behind the rostrum, but is quite immovable as usual. They are pro- 

 vided with 9 sensory papilla, and with a delicate hair standing close to 

 the posterior border of the rostrum. 



The second pair of antenna presents no peculiarity of its own. 

 They are slender and rather short, not reaching the posterior border of 

 the shell if laid backwards. The natatory hairs are also feebly developed. 

 The basal segment of the antenna as well as its two branches are covered 

 with transverse rows of minute setae. 



The tail (Fig. 6) is provided with four well-marked dorsal processes, 

 the first of which — " Verschlussfalte " of the German authors — is slender 

 but high, bending forwards in the usual manner. The second process is 

 as broad as or broader than the first, and is bent backwards ; it is nearly 

 two-thirds as high as the first. The third process is much lower than 

 the second, and the fourth still lower. This last is not always of the 

 same development, sometimes appearing only as a small elevation behind 

 the third. The suj-face of the first process is smooth, but those of the 

 other are beset with small hairs. The upper border of the post-abdomen 

 is nearly straight tapering evenly towards the apex. Its lower border 

 has a slight curvature at the anal region, otherwise it is nearly straight. 

 It is provided with about 10-16 anal denticles standing at nearly equal 

 distances from one another, and their sizes gradually diminish backwards. 

 The apical claws (Fig. 7) are greatly curved, and are quite even on their 

 dorsal sides. The basal third of the ventral sides are, however, provided 

 with two sets of closely set teeth, whose number varies greatly according 

 to different individuals. Beyond the teeth and at the same level with 

 them a delicate ciliation can be traced nearly to the tip. The caudal 

 setae are short and are of usual shape. 



