ON A NEW GENUS OF TERRESTRIAL 1SOPODA. 61 



Description of Paracubaris spinosus, a new Genus and Species of Terrestrial 

 Isopoda from British Guiana. By Walter E. ■ Collinge, D.Sc, 

 F.L.S., etc., Carnegie Fellow, and Research Fellow of the University of 

 St. Andrews. 



(Plate 6.) 

 [Read 3rd May, 1917.] 



In June last I received from Mr. G. E. Bodkin, the Government Economic 

 Biologist at Georgetown, Demerarn, British Guiana, two specimens of 

 Terrestrial Isopods collected from decaying wood, Mazakuvi River, British 

 Guiana, a very slight examination of which was sufficient to indicate that 

 they differed in a number of important structural characters from the genus 

 Cubans, Brandt, to which they bore a superficial resemblance. 



A closer examination shows that whilst belonging to the Cubaridse, they 

 are quite distinct from the genus Cubaris or any of its allies, and necessitate 

 the erection of a new genus, which I am here describing under the name of 

 Paracubaris. 



Paracubaris, gen. nov. 



Body oblong-oval, segments strongly convex, whole of dorsal surface 

 covered with short, blunt spines. Oephalon short and wide, cephalic lobes 

 absent, epistome dorsally sloping and keeled in the median line. Eyes 

 compound, situated dorso-laterally. Antennas with 2-jointed flagellum and 

 elongated terminal style. Inner lobe of maxillipede without spines, termi- 

 nating in a setaceous pad. Pleural plates of mesosomatic segments slightly 

 excavate and terminally the 2nd to 5th bluntly pointed. Only the first 

 segment exhibits a slight thickening on the inner lateral margin. Uropoda 

 extending beyond the telson ; basal plate thick and flattened, exopodite 

 articulating with the posterior inner border, short and broad and extending 

 beyond the basal plate, endopodite long, both exo- and endopodite have 

 a short terminal style. Telson triangular, terminally bluntly rounded, 

 proximally wider than the length. 



Paracubaris differs from the genus Cubaris, Brandt, in the form of the 

 cephalon, antenna;, maxillipedes, and the first mesosomatic segment. Unlike 

 any member of the latter genus the uropoda extend beyond the telson and in 

 the form of both of these structures there are well-marked differences. 



In the position of insertion of the exopodite Paracubaris shows a relation- 

 ship with Pseudarmadillo, Saussure *, Sphceroniscus, Gerstaeoker f, and 



* Rev. et Mug. Zool. (s. -J), vol. i.v. (1857) p. .108, and Mem. Soc. Phys. et d'Hist. Nat. 

 Geneve, vol. xiv. (1S58) p. 483, figs. 43, 43 a. 

 t Ent. Zeit. 1854, p. 314. 



