i8o Records of the Indian Museum. [Vol. VI, 



dazzling. It makes the inadequacy of earlier descriptions pain- 

 full}' felt. The systematist is warned against placing his trust in 

 easil}^ observed characters, for thereby he runs the risk of obscuring 

 important variations and of mixing up new species with old. As 

 might be expected, the fuller stud}^ of the various organisms has 

 led to a multiplication of genera. Many of these indeed are in- 

 troduced in the disguise of subgenera, like the rich heiresses in 

 modern works of fiction, who hire themselves out as governesses 

 or typists, just to see how it feels. As the ladies eventually come 

 by their own, so subgenera in due course turn into genera. Surely 

 they might as well have been so called from the outset. Whether 

 the status of the names be generic or subgeneric, I have in this 

 paper argued that Metoponorthus, Budde-Lund, must give way to 

 Porcellionides, Miers. Also I have found it necessary to introduce 

 two new genera by the names Paraperiscyphis and Exalloniscus. 

 Two new species are proposed, Sphaeroma annandalei in one 

 tribe and Paraperiscyphis travancorensism the other. 



Tribe FLABELLIFERA. 



Family AEGIDAE. 



1879. Aegidae, Schiodte and Meinert , Naturhist. Tidsskrift, ser. 3, 



vol. xii, p. 325. 

 1890. ,, Hansen, Cirolanidae, pp. 58 (294), 79 (315). 



Gen. Alitropus, Milne-Edwards. 



1840. Alitropus, Milne-Edwards, Hist. Nat. Crust., vol. iii, pp. 234 



{Alitrope), 245. 

 1879. ,, Schiodte and Meinert, Naturhist. Tidsskr., ser. 



3, vol. xii, p. 403. 

 1890. Rocinela {Alitropus), Hansen, Cirolanidae, pp. 80 (316), 



170 (406). 



1892. Rocinela, Max Weber, Zool. Ergebnisse einer Reise in 



Niederl. Ost-Ind., vol. ii, p. 553. 



1893. Alitropus {Rocinela), Stebbing, Hist. Crust., p. 348. 



While Hansen and Max Weber quite rightly notice the close 

 approximation of the genera Rocinela and Alitropus, there is^ a 

 notable difference between the stout structure of the anterior 

 limbs in most species of the former and their slenderness in Alitro- 

 pus typus. If some species allotted to Rocinela have these limbs 

 slender, it m.ay prove advisable to transfer such forms to Alitropus, 

 and so help to disburden Rocinela, which has recently received so 

 many additions. It is not a little unsuitable to have a Rocinela 

 typus (Milne-Edwards), which is in no sense typical of Leach's 

 Rocinela. 



Alitropus typus, Milne-Edwards. 



1840. Alitropus typus, Milne-Edwards, Hist. Nat. Crust., vol. iii, 

 p. 247, pi. 33, figs- 1-7- 



