194 Mr. E. J. Miers on a Freshwater Crustacean. 



were collected by an American gentleman, Dr. Wliitman, who 

 describes them as occurring very abundantly in fresli water 

 (not brackish) ponds and ditches in the vicinity of Tokio, 

 Japan. Their embryology and development, I am informed,^ 

 is being studied by Mr. Ishikawa, of the University of 

 Tokio. 



These specimens I find upon examination to be very pro- 

 bably identical with the species long ago described by De 

 Haan * as Epliyra ? comp'essa^ which von Martensf refers to 

 the genus Atyephyra, Brito-Capello. As the specimens 

 before me differ in some particulars from the published de- 

 scriptions, I have thought it useful to place on record the few 

 following notes, which were made while endeavouring to 

 determine the species. 



Afyephyrn conqjressa has been hitherto a desideraiuni to 

 the British Museum ; nor have we at present in the national 

 collection any specimens of the genera to which it is appa- 

 rently most nearly allied — Troylocaris, T>ovmitzer, and 3[iersia, 

 Kingsley {=Epliyra, Roux). My observations, which refer 

 only to the external characters proper for distinguishing the 

 genera and species, will, I trust, in no way interfere with, but 

 merely supplement Mr. Ishikawa's work, which will, I 

 believe, ere long be published. 



Atyephyra compressa differs from the Portuguese species, 

 Atyepliyra rosiana^ on which Brito-Capello founded the 

 genus A tyephyra |, in that the palpiform appendages articu- 

 lated with the bases of the thoracic limbs (exopodites) are 

 wanting to the three posterior pairs in A. rosiana, and the 

 palm or penultimate joint in the first and second legs is some- 

 what excavated at its proximal end. I have not either the 

 time or material necessary for a comparative study of the 

 genera of Atyidte ; but I think it probable that the presence 

 of these palpi upon all the thoracic limbs in the Japanese 

 species may be a character sufficient to separate it generically, 

 when I would propose to designate it Paratya. There are 

 specimens in the collection of the British Museum from 

 a freshwater stream near Cintra, presented by the Eev. A. 

 E. Eaton, that I refer to Atyepliyra rosiana, which only 

 differ from Brito-Capello's specific description in having the 



* In von Siebold's ' Fauna Japonica/ Crustacea, p. 18(3, pi. xlvi. fig. 7 

 (1849). 



t Archiv f. Naturgescliichte, xxxiv. p. 51, pi. i. fig. 4 (1808). 



X " Descrip^ao de algunas especies de Crustaceo.s, tSrc," in Mem. Ac, 

 Sci. LisLoa, iv. p. 01, pi. i. tig. 1 (1807). 



