ISOPODS OF NORTH AMERICA. 631 



nous antero-lateral lobes. Epi.stome very ])ull)ous, separated from 

 the front by a tran«vei'se groove. 



Lateral parts of the thoracic segfments small. 



Abdomen abriq)tly narrower than thorax; terminal seo'ment short, 

 triangular, extending* much be3ond the epimera of the preceding 

 segment. 



First and second pairs of pleopods furnished with tracheae. 



RHYSCOTUS TURGIFRONS ( Budde-Lund). 



Stenoinacrxis tnrglfrons BuDHE-LrND, IVosj). gencrnni 8i)ecieruin(ine Crust. Isop. 

 Terrestrium, 1879, p. 5. 



Rhi/scotus turgifrons Budde-Lund, Crust. Isop. Terrestria, 1885, p. 192. — Rich- 

 ardson, Proc. U. S. Nat. Mus., XXIII, 1901, p. 569. 



Locality. — St. Jean, West Indies. 



Body oblong, posteriorly attenuated, rathei- convex, minutely and 

 densely punctuate and covered with scattered hairs. The inner face 

 of the mandibles is furnished with two plumose processes(^). 



The second pair of antennae are longer than half the length of the 

 body; the first article of the flagellum is almost half as long as the 

 second. 



The terminal a])dominal segment is short, with the sides slightly 

 incurved, the apex obtuse; it is sulcate above. The uropoda are 

 rather long; the basal article is longer than the terminal segment of 

 the abdomen; the outer branch is conical; the inner branch is slender, 

 a little curved, with the apex furnished with hairs. 



Color brownish black, lighter on the epimera; ventral side a dark 

 gray; legs dark. Length, 5 mm.; width, 2 mm.; height, 1.8 mm.^' 



113. HYPERGNATHUS, new genus. 



Head with antero-lateral lobes obsolete; front not margined but con- 

 tinuous with epistome. Flagellum of second pair of antenna? composed 

 of two articles, the second one being nmch longer than the first. 

 Mandibles without molar expansion; recurved brush-like appendage 

 wanting. First maxillas with the inner lobe furnished with two plu- 

 mose processes at the tip; outer lobe furnished with numerous spines 



«The above description is adapted from the following one of Budde-Lund's: 



Oblongus, jjost attenuatus, convexiusculus, minute et dense punctatus, sparse 

 crinitus. Mala interior mandibularum penieillis binis(?). 



Antennte exteriores corpore dimidio longiores, flagelli articnlns i)rior altero fere 

 duplo brevior. 



Cauda? annulus analis brevis, lateribus leviter incurvis, apice obtuso, supra sul- 

 catus. Pedes anales longiusculi; articulus basalis annulo anali sublongior; ramus 

 exterior terminal is conicus; ramus interior tenuis, paululum curvatus, apice setaceo. 



Color e nigro brunneus, in epimeris dilutior; venter e fusco griseus; pedes fusci. 



Longitudo, 5 mm.; latitudo, 2 mm.; altitudo, !.:> mm. — Bi-dde-Lund, Crust. Isoj). 

 Terrestria, 1885, p. 192. 



