PHYLLOPOD CRUSTACEA OF JAPAN. 149 



spherical shape, but their number seems to be fewer than in that 

 species, 5-6 being seen projecting at the pariphery of the black pigment. 

 The ocellus is of an irregular pentagonal shape, and lies nearly in the 

 midway between the eye and the posterior border of the head. 



The first pair of antenual is situated just behind the rostram and is 

 quite immovable as usual. It is provided with 9 olfactory setae and 

 with a very delicate hair close to the posterior border of the rostrum. 



The second pair of antenna is perhaps slightly smaller than in D. 

 Morsei, but is similary constructed. Its basal segment as well as its 

 two branches are also covered with transverse rows of minute setae as 

 in that species or in D. pulex or in D. pennata. 



The dorsal side of the tail is also provided with four well-marked 

 processes, but the anterior two of these are relatively a little lower, and 

 the surface of all the processes are covered with small hairs. The 

 upper border of the post abdomen is slightly and evenly curved, passing 

 gradually to tlie apical claw. Its lower border is nearly straight, and 

 is provided with, in most cases, 9 rather straight anal denticles standing 

 at equal distances from one another, and their sizes gradually diminish 

 backwards (Fig. 4 a.). In some large specimens greater number of 

 denticles are sometimes met with, but is always fewer than in D. Morsji, 

 13 being the greatest number counted. The apical claw is strongly 

 curved at its extreme end, and its dorsal border is provided with two 

 denticles, the proximal one of which is nearly twice as large as the 

 distal one. The basal third of its ventral border is, like that of the 

 preceding species, provided with two sets of teeth, the proximal and the 

 distal, the latter of which consists of 7 or 8 rather stout teeth, while the 

 pi'oximal set consists of numerous fine teeth, the two anterior of which 

 being much larger than the other. Beyond the teeth and at the same 

 level with them a delicate ciliation can be traced up to the apical 

 cuL'vature of the claw. The caudal setae are short and are of usual 

 shape. 



The ccEcal processes are slightly larger and a little more curved 

 than in D. Morsei. 



