128 



SIIIGEMI ISHII. 



group, the legs are more or less anteriorly directed, while in the posterior 

 they are posteriorly directed. In both groups, the foremost situated pair, 

 i. e. the first and fourth pairs, arc the smallest, and the remaining pairs in 

 each group increase in size posteriorly. This feature is especially con- 

 spicuous in males. On the whole, tke first pair is the smallest ot all and 

 the seventh pair the largest. All the legs are similarly constructed (fig. 7). 

 Dactylus and propodus are more strongly developed in the present species 

 than in Ichthyoxenus japonensis ; carpus, meros and ischium are compara- 

 tively small and not inflated, unlike the same joints in the species just 

 mentioned, in which they, but especially the meros, are much inflated 

 ventrally. 



Pleopods large, lamellar. 

 Jixopodite usually a little larger 

 than endopodite, subcircular in 

 outline ; endopodite half-moon- 

 shaped or reniform. Endopodite 

 of second pair (fig. 8) with an 

 " appendix masculina " in both 

 sexes, not restricted to males 

 only, as it is in IehtJiyoxenus 

 japonensis. The said appendix 

 is moderately long, rod-like, 

 slightly tapering towards free 

 end, 1.57 mm. long and about 

 0.1 mm. broad in the middle. 

 Third, fourth and fifth pairs of 

 pleopods with a small knob-like 

 projection at anterior inner edge 

 of endopodite. In the first pair, 

 however, no such projection 

 present. Surface of pleopods covered with small clear spots arranged 

 more or less regularly in transverse rows. Size of these spots a little 



Fig. 7, Seventh thoracic leg, X15. 



Fig. 8, Second pleopod, X15. 



Fig. g, Uropod, X15. 



Fig. 10, Second (a) and fifth (b) pleopods of 

 larva. Magn. about 48 X . 

 ap. — " Appendix masculina," 

 en. — Endopodite, ex.— Exopodite. 



