PHYLLOPOD CRUSTACEA OF JAPAN. 99 



portion on its upper side. The median portion is shorter (nearly | that of 

 the basal portion), and thinner, and passes over to the enlarged distal portion 

 which soon divides into tv/o branches, each of which is nearly as long as the 

 basal portion ; these give off a large branch from its inner anterior side near 

 the base and a small one from the outer posterior side near the apex ; a small 

 branch ending in a narrow process is again seen from the basal portion of 

 the larger branch. On both the outer sides of the two first portions of the 

 frontal process is seen a series of about thirty-one tactile (?) papillae, which 

 gradually decrease in size from the basal portion forwards. A number of 

 similar but smaller papillae is also seen on the branches of the terminal portion. 



Telson nearly twice as large as the last abdominal segment ; caudal 

 appendages long and slender, with numerous plumose setae on each side. 



The male reproductive organs are long, slender tubes of nearly equal 

 thickness, and extend from the last abdominal segment forwards to the 

 front end of the ninth segment counting forward from the telson inclusive, 

 where they turn downwards and outwards, and making a small loop ascend 

 perpendiculary when they again bend inwards till they nearly meet with each 

 other in the median line of the body of the animal ; they then make an 

 abrupt turn outwards and run for a short distance posteriorly, where they 

 again turn abruptly inwards and forwards, then outwards and downwards, till 

 they reach the ventral side of the segment, whence they enter into the 

 copulatory organ — the penis. This is a paired retractile tube, arising from 

 the first and second segments of the abdomen, directed backwards and 

 downwards with the terminal end enlarged and knob-like, and beset with 

 numerous recurved spicules on their entire surface. The sperm-cells as 

 usual round with many granular chromosomes. 



Female. — Both the stalked and median eyes similar to those of the 

 male. The first antennce are also quite similar to those of the male. The 

 second antennce flattened, a little shorter than the stalked eye, bent down- 

 wards, its anterior, outer side more curved than its posterior inner side ; it is 

 two jointed with a short basal and a flattened terminal joint ending in a 

 pointed process which rises from its posterior side. Both the anterior and 

 the posterior edges of the second antennae covered with minute setae. 



