116 



On Three Species of Isopod Crustacea found in 

 the nests of ants in south australia. 



By W. H. Baker, F.L.S. 



[Read May 8, 1913.] 



Plates II. and III. 



In 1894 Wasmann — Kritisches verzeichniss de myrme- 

 kophilen und termitophilen arthropod en, Berlin, 189^ — • 

 enumerated nine species of Oniscoidea found in association, 

 with ants in their nests. The list is as follows : — 



1. Metoponorthus myrmeco'philus. Stein, Dalmatia. 



2. Platyarthrus hoffmanseggi, Brandt, Europe. 



3. ,, schhohli, Budde-Lund, Canary Islands. 



4. ,, caudatus, Aub. et Dollfus, Europe. 



5. ,, simoni, Dollfus. 



6. Lucasius (Porcellio) pallidus, S. France. 



7. ,, hirtus, Aub. et Dollfus, Marseilles. 



8. ,, myrmeco'philus, Luc. 



9. Leptotrichus inquilinus, Klbl., Somali Coast. 



To these must be added — 



10. T?Hchoniscus commensalis, Chilton, New Zealand. 



Of the three species here described the first two have been 

 found together in the nests of Gamponotus nigriceps in several 

 parts of this State, and the first also with Myrmecia forficata. 

 I am of opinion that these will be recorded from nests of other 

 species of ants. That they are true Myrmecophiles there seems 

 to be no doubt. The third is from a termite's nest, and may 

 probably also be found with ants ; it is a very minute species 

 of about 2 mm. long, and consequently very difficult to handle. 



I am indebted to Mr. A. M. Lea, of the South Australian 

 Museum, for many specimens ; also for the names of the ants. 



ISOPODA. 



Tribe, ONISCOIDEA. 



Family, ONISCID^. 



Genus, Oniscus, Linn. 



Oniscus myrmecophilus, n. sp. Plate ii., figs. 1-10. 



The body is little convex, with minute scale-like hairs, 

 which are not crowded. 



The head is rather rough, about three times broader than 

 long ; it projects a little medianly, being declivous anteriorly ; 



