598 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



1O4. Genus LYPROBIUS Budde-Lund. 



Body not convex, scarcely contractile. Head produced into lobes 

 at the side; front not produced in the middle, marginate. Epimera 

 of the third, fourth, and fifth segments of the abdomen large. 



Peduncle of the uropoda short and wide, with the outer side silicate. 



Epimera of the thoracic segments moderately large; those of the 

 first three segments with the posterior angles roundly obtuse, those 

 of the fourth segment with the posterior angles straight, and those of 

 the three posterior segments with the posterior angles acute. 



Body setigerous, scarcel} 7 granulated. 



Flagellum of second antennae composed of three articles. 



LYPROBIUS PUSILLUS Budde-Lund. 



Lyprobius pusillus BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 230. RICHARD- 

 SON, Proc. U. S. Nat. Mus., XXI, 1899, p. 864; Ann. Mag. Nat. Hist. (7), 

 IV, 1899, p. 333; American Naturalist, XXXIV, 1900, p. 305. 



Locality. California. 



Body oval, rather convex, smooth, punctate, very minutely setiger- 

 ous, especially so posteriorly. 



Second pair of antennae a little shorter than half the length of the 

 body; first article of the flagellum equal in length to the third, almost 

 half as long as the second. 



Antero-lateral lobes small, rounded. Front, with the median mar- 

 ginal line entire, a little arched and produced. 



The terminal segment of the abdomen is triangulate in the middle, 

 produced, and extends a little beyond the epimera of the fifth abdom- 

 inal segment; terminal segment a little excavate above. 



Color uniformly brown, transparent on the margins, white. 



Length 5 mm. Width 2.5 mm. Height 1.2 mm. 6 



1O5. Genus SYNUROPUS Richardson. 



Body oval, not contractile into a ball, with the segments laterally 

 expanded, as in Oniscm. 



Head with lateral and frontal lobes. Second pair of antennae long, 

 with fiagellum composed of three articles. 



o For characters of genus see Budde-Lund, Crust. Isop. Terrestria, 1885, pp. 229-230. 



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



Ovalis, convexiusculus, sublaevis, punctatus, minutissime praesertim post setiger. 



Antennae exteriores corpore dimidio paulo breviores; flagelli articulus primus 

 tertio eequalis. secundo fere duplo brevior. 



Lobi frontales laterales parvi, rotundati. Frons media linea marginal! integra 

 paulum curvate producta. 



Caudse annulus analis medio triangulo, producto, epimera annuli praeanalis paulum 

 superante, supra paulum excavatus. 



Color uniformis brunneus, in marginibus perlucens, albidus. 



Longitudo 5 mm., latitude 2, 5 mm., altitude 1, 2 mm. BUDDE-LUND, Crust. 

 Isop. Terrestria, 1885, p. 230. 



