ISOPOD8 OF NORTH AMERICA. 631 



nous antero-lateral lobes. Epistome very bulbous, separated from 

 the front by a transverse groove. 



Lateral parts of the thoracic segments small. 



Abdomen abruptly narrower than thorax; terminal segment short, 

 triangular, extending much beyond the epimera of the preceding 

 segment. 



First and second pairs of pleopods furnished with tracheae. 



RHYSCOTUS TURGIFRONS (Budde-Lund). 



Stmomacrus turgifrom BUDDE-LUND, Prosp. generum specierumque Crust. Isop. 

 Terrestrium, 1879, p. 5. 



Rhijscotus 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, rather 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 abdominal 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, 1.3 mm." 



113. HYPERGNATHUS, new genus. 



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

 tinuous with epistome. Flagellum of second pair of antennae composed 

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

 Mandibles without molar expansion; recurved brush-like appendage 

 wanting. First maxillae 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, post attenuatus, convexiusculus, minute et dense punctatus, sparse 

 crinitus. Mala interior mandibularum penicillis binis(?). 



Antennae exteriores corpore dimidio longiores, flagelli articulus prior altero fere 

 duplo brevior. 



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

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

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



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



Longitude, 5 mm.; latitude, 2 mm.; altitude, 1.3 mm. BUDDE-LUND, Crust. Isop. 

 Terrestria, 1885, p. 192. 



