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 trachee. Mr. 
Whyinper 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. 
Rhyscotus, Budde-Lund, 1885, has a single species, 
Rhyscotus turgifrons from the West Indies. 
Leptotrichus, Budde-Lund, 1879, ‘with fine hairs,’ 
receives four species, to which Dollfus doubtfully adds his 
Syrian Porcellio pulchellus. He also records Leptotrichus 
tauricus, Budde-Lund, from the Mount of Olives. 
Bathytripa, Budde-Lund, 1879, ‘with deep haunts,’ 
has two or three species. 
Incasius, Kinahan, 1859, is reinstated by M. Eugéne 
Simon in 1885, to receive not only the Algerian Por- 
cellio myrmecophilus, 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 Platy- 
arthrus. He describes a new species Lucasius hirtus from 
Marseilles, and from the same district records Lwucasius 
pallidus (Budde-Lund). 
Chavesia, Dollfus, 1889, agrees with the preceding 
genera in having the flagellum of the second antennz 
two-jointed, but with Armadilloniscus 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 antenne. 
Platyarthrus, Brandt, 1833, has the body broad and 
flattened, no eyes, the flagellum of the second antennz 
small, with its first joint inconspicuous. Platyarthrus 
Hoffmannseggu, 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, 
