Art. VI. — Janirella, a Neio Genus of Isoj^oda from 

 Fresh-water, Victoria. 



By O. a. SAYCE. 



(Plates XVIII. and XIX.) 

 [Read 10th May, 1900.] 



The Isopod here described I collected from a small fresh-water 

 pool at Thorpdale, Gippsland, at the same time and place that I 

 took Phreatoicoides gracilis and Niphargus ptdchelhis. In my two 

 papers describing these forms^ I mentioned the locality in some 

 detail. The present species was an inhabitant of the same little 

 pool as N. pulchellus. 



It is a normal member of the family Janiridae as defined by 

 Sars in 1897,^ except in being blind, and in this respect it agrees 

 with the Isopod and Amphipod mentioned above. It is also 

 remarkable as having a fresh-water habit. Sars, in his remarks 

 on the family, says that, " all the known forms are exclusively 

 marine, and, as it were, replace the Asellidae in the oceans " ; but 

 I might point out that Jaera guemei, Dollfus (the genus being 

 undoubtedly of this family) had previously been recorded as an 

 inland river species of the Azores.^ 



It seems necessary to form a new genus for the present species, 

 and, because of its possessing many characters in affinity with 

 both Janira and /atiiropsis, I propose to name it Janirella. 



Janirella, n. g. 



Ge/ieral Characters. — General form of female that of Janira ; 

 the male is smaller, with each segment wider, or at least as wide, 

 as the preceding one ; in other respects, except in the pleopodos, 

 similar in form in both sexes. Caudal segment large, as long, or 

 longer, than broad, rounded distally. Segments of peraeon with 

 lateral margins not laciniate. Superior antennae small, with 

 flagellum rudimentary. Inferior antennae very much elongated, 



1 Proc. Royal Societj' Victoria, vol. xii., pp. 122 and 152. 



2 Sars, Crustacea of Norway, ii., pts. 5, 6, p. 98. 



3 Stebbing, History Crust. 1893, Int. Sc. Series Ixxiv., p. 379. 



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