AN ANOMALOUS JOINT 431 
mountain forests of Corsica, a ‘ beautiful species, hitherto 
the largest of the genus,’ Philoscia celleria, 1884, from 
Marseilles, and Philoscia anomala, 1890, a species brought 
by the Challenger from Valparaiso and Juan Fernandez, in 
which the adult male, perhaps in the marital stage, has 
the fifth joint (tarsus) of the fourth pair of feet developed 
into an almost circular disc. Dollfus remarks that Oniscus 
bucculentus, Nicolet, is really a Philoscia, which also ex- 
hibits this apparently anomalous and perhaps temporary 
character. 
Alloniscus, Dana, 1854, has seven species described by 
Budde-Lund, of which the first is Alloniscus perconvexus, 
Dana, from California; the last is Alloniscus cornutus, 
Budde-Lund, strongly exhibiting the generic character in 
having the lateral frontal processes of the head large, 
narrow, prominent, subconical, and the middle of the front 
very tumid. Jn addition to the seven species, Rhinoryctes 
mirabilis, Stuxberg, 1875, from California, is said certainly 
to belong to Alloniscus. 
Lyprobius, Budde-Lund, 1875, receives three species. 
Scyphaz, Dana, 1852, has the species setiger, Budde- 
Lund, from New Caledonia, and ornatus, Dana, from a 
sandy beach of New Zealand. 
Deto, Guérin, 1854, is said to be very near Oniscus. 
Deto echinata, Guérin, and Deto acinosa, Budde-Lund, are 
both African species. 
Armadilloniscus, Uljanin, 1875, has the flagellum of the 
second antennz four-jointed. Budde-Lund, besides de- 
scribing three species, incorporates with them Actoniscus 
ellipticus, Harger, and with hesitation also Actccia euchroa, 
Dana, and Actecia Aucklandic, G. M. Thomson, both from 
New Zealand. Dollfus adds Armadilloniscus tuberculatus, 
1889, from the Azores. In this genus the uropods are 
flattened and scarcely produced, the peduncle large, and 
the outer branch short, just reaching the apex of the 
peduncle. 
Scleropactes, Budde-Lund, 1885, has the body very 
convex and contractile into a globular form, the opercular 
branch in all the pleopods tracheal, and the uropods toler- 
