rHILLOroD CllASTACEA OF JAPAN. 



is 



forU- ri iioi-tb of Tokyo, daring the month of August I8U4. Of about one 

 hundred specimens given to me by this gentleman, no single male is to be 

 found among then] ; but as all the females are still young, carrying no eggs 

 under the shell, it is not certain whether the specimens before me are the 

 parthenogenetic genci-ation of a cyclic species, or the females of a gamogenetic 

 generation in which the males have as yet not appeared, or lastly the forms 

 in which the niales have entirely disappeared like those of Limnadia Her- 

 maimi of J^^urope. Further researches are necessary for the determination 

 of these points. 



It will be seen from the above description, that this species differs from 

 all the known species of Limnadia and Eulimnadia in having fewer lines of 

 growth on the shell. The general shape of the body, as well as the posses- 

 sion of twenty-two pairs of legs makes it quite certain that it belongs to the 

 Genus Limnadia of Packard,* which according to this author should possess 

 about eighteen lines of growth. I do not, however, lay any great stress on 

 this point, since all the specimens are, as said before, still young, and there 

 is a great i)robability of the increase of the size of the shell together with 

 that of the luunber of the lines of growth. The more so, since all the 

 specimens with three lines of growth are larger than those with two, and 

 s(jme few small animals are found among them possessing only one line oi 

 growth. But as the number and the shape of the legs, the number of the 

 anteimal segments as well as the general shape of the body are similar in 

 smaller specimens with only one line of growth as in those with three lines, 

 I venture to consider the present specimens to have attained all the adult 

 structures and to distinguish them as a new species of Limnadia. 



LULHINADLV BKAUEEIANA,' n. spec. (VI. VIII). 

 Male (Fig. 1) : — Shell valves thin, trans[)arent and bhining, of a pale 

 greenish colour, ellipsoidal, about two-third as broad as long, almost of 



* A. S. Packard. Jr.— A Monograph of North American Phyllopod Crustacea; Twelfth 

 Annual Report of the United States Geological an<l Geographical Snrvej% \Vashington, 1883. 

 pp. 311. 



t Didicatoil to Dr. Friodricli JJrauor. 



