XII. INDIAN ISOPODS. 



By the Rev. Thomas R. R. Stebbing, M.A., F.R.S., 

 F.L.S., F.Z.S. 



Some time ago Dr. Annandale entrusted me with a small col- 

 lection of Isopoda from the Indian Museum, mostly terrestrial 

 species, but some of aquatic though not marine habitat. The pres- 

 ent paper is concerned with a part of this collection, distributed 

 between the two tribes of the Flabellifera and the Oniscidea. 



In the former tribe only the genera Aliiropus and Sphaeroma 

 are here represented. But I may take this opportunity of calling 

 attention to two other generic names included in it. The elder 

 of these is Rhexana, Schiodte and Meinert, 1883, in the family 

 Cymothoidea. It has recently been again brought into notice by 

 Dr. Thienemann in his excellent Contributions to the knowledge of 

 the Isopod-fmma of East Asia, 19 10. This name, however, which 

 is not recorded in Scudder's Nomenclator Zoologicus, 1882, was 

 preoccupied by Dr. Sorensen in 1879.^ I therefore propose as a 

 convenient substitute for it the form Rhexanella, still at present 

 contented with the single species R. verrucosa, for which the 

 genus was founded. The other generic name in question is Bro- 

 therus, Budde-Lund (in Voeltzkow's Reise in Ostafrika, vol. ii, 

 p. 306, 190S), included b}- its author in the family Alcironidae, 

 Hansen, which, as pointed out in 1904, should rather be called 

 Corallanidae. But Brotherus is not distinguishable from Arga- 

 thona, which I named in 1905, in a new family Argathonidae, unless 

 the fusion of the fourth and fifth joints in the maxillipeds of A rga- 

 thona normani suffices to distinguish that type species generically 

 homBroiherns longicornis, Budde-Lund, 1908, and Argaihona reidi^ 

 Stebbing, 1910, in which there is no such fusion. This distinction 

 being disregarded, all three species will belong to Argathona, but 

 if on the contrary it be thought to have generic value, Argathona 

 reidi must be transferred to Brotherus. 



With regard to the tribe Oniscidea it is well known that Budde- 

 Lund's Isopoda Terresiria, 1885, was for long the leading treatise 

 on the subject. Then for a considerable period the study was left 

 almost entirely to the industry of M. Adrien DoUfus. During 

 the last few years, however, there has been a great change. Many 

 capable authors have found the group attractive. Instead of 

 scanty illustrations or none at all, copious and elaborate drawings 

 of structural details have been supplied, especially in the works 

 of Sars, Racovitza and Budde-Lund. The new light is somewhat 



1 N aturhistorisk Tidsskrifi, ser. 3, vol. xii, p. 124, footnote. Rhexana is here 

 substituted by Sorensen for the preoccupied name Anelasma which he gave to a 

 genus of Opiliones in 1873. 



