A MOUNTAINEER 429 



two pairs. Another British species, which is said to be 

 cosmopolitan, is Metoponorthus pruinosus (Brandt). It 

 belongs to the section with two pairs of tracheae. Mr. 

 Whymper found it in Ecuador at a height of 13,300 feet 

 above the sea, highest soaring of the Isopoda. Dollfus 

 describes Metoponorthus Barroisi, 1889, from the Azores, 

 and in 1892 two new species from Palestine. 



Rliyscotus, Budde-Lund, 1885, has a single species, 

 Rhyscotus turgifrons from the West Indies. 



Leptotrwlius, Budde-Lund, 1879, 'with fine hairs,' 

 receives four species, to which Dollfus doubtfully adds his 

 Syrian Porcellio pulchellus. He also records Leptotriclius 

 tauricus, Budde-Lund, from the Mount of Olives. 



Bathytropa, Budde-Lund, 1879, 'with deep haunts,' 

 has two or three species. 



Lucasius, Kinahan, 1859, is reinstated by M. Eugene 

 Simon in 1885, to receive not only the Algerian Por- 

 cellio myrmecophiliiS) Lucas, for which it was instituted by 

 Kinahan, but also three other species, pallidus, tardus, 

 and. pauper, named by Budde-Lund and by him referred to 

 Porcellio. In 1890 Dollfus likewise remarks that Lucasius 

 ought to be extended to a whole group of the ancient 

 genus Porcellio, formed of ant-loving species, with charac- 

 ters morphological and biological near to those of Platt/- 

 arthrus. He describes a new species Lucasius hirtus from 

 Marseilles, and from the same district records Lucasius 

 pallidus (Budde-Lund). 



Chavesia, Dollfus, 1889, agrees with the preceding 

 genera in having the flagellum of the second antennae 

 two-jointed, but with Armadittoniscus more nearly in the 

 structure of the uropods. Chavesia costulata, Dollfus, is 

 from the Azores. By an obvious misprint the description 

 assigns the two-jointed flagellum to the first antennae. 



PlatyarthmSj Brandt, 1833, has the body broad and 

 flattened, no eyes, the flagellum of the second antennas 

 small, with its first joint inconspicuous. Platyarthrus 

 Hoffmannseggii, Brandt, appears to be met with almost all 

 over Europe, but never except in ants' nests. In addition 

 to the English localities named by Bate and Westwood, 



