NEW GENUS OF TEERESTEIAL ISOPODA. 509 



Description of a new Genus and Species of Terrestrial Isopoda from British 

 Guiana. By Walter E. Collinge, M.Sc, F.L.S., F.E.S., Research 

 Fellow of the University of St. Andrews. 



(Plate 50.) 

 [Read 4th March, 1915.] 



The Terrestrial Isopoda of the South American continent have as yet received 

 very little attention, although one cannot help thinking that there is a large 

 and interesting fauna awaiting investigation. From different parts, species 

 have been described by Miers (1), Budde-Lund (3), Dollfus (3, 4, 5, 6), and 

 Richardson (7), but in all probability these constitute only a very small part 

 of the actual indigenous fauna. 



Some few months ago Mr. G. E. Bodkin, the Government Economic 

 Biologist at Georgetown, Demerara, British Guiana, very kindly forwarded 

 to me for identification a number of specimens collected beneath the bark of 

 trees in the Botanic Gardens, Georgetown. Two of the specimens (both 

 imperfect) are referable to the cosmopolitan species Porcellionides pruinosus 

 (Brandt), whilst the remaining ones, in various stages of growth, belong to 

 a new genus and species here described under the name of Calycuoniscus 

 bodkini. 



Calycuoniscus, gen. nov. 



Body oblong-oval, flattened ; metasome a little narrower than the mesosome, 

 the cephalon and segments covered with peculiar cup-shaped or calyx-like 

 organs, and the appendages marked with lattice-work and scale-like ornamen- 

 tation. Cephalon with well-developed median and lateral lobes, the former 

 being prolonged forwards and slightly downwards ; epistoma raised in the 

 median line, at each side of which is a deep concavity. Antennae of medium 

 length with 3-jointed flagellum, divisions subequal. Uropoda extending 

 beyond telson, globose, basal plate with raised anterior margin ; exopodite 

 short and thick, outer border almost straight ; endopodite same length as 

 exopodite, both setaceous with terminal hair-like setse. Telson triangular 

 with posterior margin bluntly rounded. 



Affinity doubtful. 



Calycuoniscus bodkini, sp. nov. 



Body (fig. 1) oblong-oval, flattened ; metasome a little narrower than the 

 mesosome, the segments of both, and also the cephalon, covered with peculiar 



