AN ANOMALOUS JOINT 431 



mountain forests of Corsica, a ' beautiful species, hitherto 

 the largest of the genus,' Philosda oelleria, 1884, from 

 Marseilles, and Philosda 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. DoUfus remarks that Oniscus 

 hucculentus, Nicolet, is really a Philosda, which also ex- 

 hibits this apparently anomalous and perhaps temporary 

 character. 



Alloniscm, Dana, 1854, has seven species described by 

 Budde-Lund, of which the first is Alloniscus perconvexus, 

 Dana, from California ; the last is Alloniscus comutus, 

 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. In addition to the seven species, Bhinoryctes 

 mirabilis, Stuxberg, 1875, from California, is said certainly 

 to belong to Alloniscus. 



Lyprobius, Budde-Lund, 1875, receives three species. 



Scyphax, Dana, 1852, has the species setiger, Budde- 

 Lund, from New Caledonia, and ornatus, Dana, from a 

 sandy beach of New Zealand. 



Beto, Gugrin, 1834, is said to be very near Oniscus. 

 Deto eehiTUita, Guerin, and Deto adnosa, Budde-Lund, are 

 both African species. 



Armadiiloniscus, Uljanin, 1875, has the flagellum of the 

 second antennee four-jointed. Budde-Lund, besides de- 

 scribing three species, incorporates with them Actoniscus 

 elUpticvs, Harger, and with hesitation also Actcecia euchroa, 

 Dana, and Actcecia Aucklandice, G. M. Thomson, both from 

 New Zealand. Dollfus adds Armadiiloniscus 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- 



