REV. T. E. E. STEBBING ON A FEESHWATER ISOPOD. 39 



A Freshwater Isopod from Calcutta. 



By the Rev. T. H. E. Stebbing, M.A., F.R.S., Sec.L.S. 



(Plate 6.) 



[Read 17th January, 1907.] 



The interest o£ the specimens about to be described hes more in the novelty 

 of their habitat than in any striking features of specific distinction. 

 Dr. Annandale, writing on the 24th October, 1906, says: — "The species is 

 evidently rare, as the three specimens are the only ones I have been able to 

 find in a very large number of sponges examined. The two smaller ones 

 were found last week in the same pond, while the larger one came from a 

 different pond last month. I am working at the freshwater sponges of this 

 district and their inqnilines, so that I am very anxious to have the different 

 species found associated with the sponges identified." 



It may be noticed that the true limits of the family Corallanidce, to which 

 these specimens belong, have only recently become susceptible of definition 

 through the researches of Mr. Stanley Gardiner in the Maldive and Laccadive 

 Archipelagoes and those of Dr. Willey at Ceylon. The scarcity of a species 

 often disappears when the attention of naturalists has been directed to it, but 

 for the moment we have the singularity of an apparently rare species of an 

 uncommon family presenting itself under conditions which are not very 

 usual for the order of isopods in general. 



Family CORALLANID^. 



1904. CorallanidcB, Stebbing, in Gardiner's Fauna of Maldive and Laccadive Archipelagoes, 

 vol. ii. pt. 3, p. 703. 



1904. Corallanidce, Stebbing, Spolia Zeylanica, vol. ii. pt. 5, p. 13. 



1905. Corallanidce., H. Richardson, Bull. U. S. Nat. Mus., No. 54, p. 156. 



In her monograph on the isopods of North America, referred to above, 

 Miss Richardson has incorporated in this family a new genus Tyidentella, and 

 the genus Nalicora published by H. F. Moore in 1902. Both of these 

 genera have seven-jointed maxillipeds, the palp being distinctly five-jointed. 



Genus TAGHiEA, Schiodte ^ Meinert. 



1879. Tachcea, Schiodte & Meinert, Naturhist. Tidsskr. ser. 3, vol. xii. p. 284. 



1890. Tachcea, Hansen, Vid. Selsk. Skr. ser. VI. vol. v. pt. 3, pp. 288, 314, 397. 



1904. Tachcea, Stebbing, in Gardiner's Fauna of Maldive & Laccadive Arch., vol. ii. p. 703. 



1904. Tachcea, Stebbing, Spolia Zeylanica, vol. ii. pt. 5, p. 14. 



In the species here described the maxillipeds are decidedly only six-jainted, 

 but the terminal joint is longer than any one of the three joints immediately 



