622 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



PorceUio montezumx SAUSSCRE, M6m. Soc. Phys. Hist. Nat. Geneve, XIV, 1858, 

 Pt. 2, p. 480, pi. v, figs. 41-41 bis. 



Porcd-lio scaber BATE and WESTWOOD, Brit. Sess.-eyed, Crust., II, 1868, p. 475. 



PorceUio paulense s HELLER, Novara Exp., 1868, p. 136, pi. xn, fig. 5. 



PorceUio scaber PLATEAU, Bull. Acad. r. Belgique, 2d ser., XXIX, 1870, No. 2, p. 

 8. E. BRANDT, Horse Soc. Ent. Rossi, VIII, 1870, p. 167. BUDDE-LUND, 

 Nat. Tidsskrift., 3d ser., VII, 1870, p. 238; Crust. Isop. Terrestria, 1885, pp. 

 129-131. SARS, Crustacea of Norway. II, 1899, pp. 176-177, pi. LXXVII. 

 RICHARDSON, Proc. U. S. Nat. Mus., XXI, 1899, p. 863; Amer. Nat., XXXIV, 

 1900, p. 3Q4; Proc. U. S. Nat. Mus., XXIII, 1901, p. 567. CHTLTON, Trans. 

 Linn. Soc. Lond., (2), VIII, 1901, Pt. 4, p. 139. STOLLER, 54th Report New 

 York State Museum, 1902, p. 213. PAULMIER, Bull. New York State Museum, 

 1905, p. 183. 



Localities. Comax, British Columbia, near Union Wharf, along the 

 shore; Taylor Bay, Gabriola Island, British Columbia, on the shore; 

 San Diego. California; Puget Sound; Oakland, California; Norwood, 

 Ohio; Westwood, Cincinnati, Ohio; Andersons Ferry, Hamilton 

 County, Ohio; Springfield, Ohio; Bering Island; Woods Hole, Mas- 

 sachusetts; Colfax, California; Ocean Grove, New Jersey; Westfield, 

 New York; Magdalen Islands; Victoria, Vancouver Island; Salem, 

 Massachusetts; Northfield, Cook County, Illinois; Beverly, Massa- 

 chusetts; Hamilton and Warwick, Massachusetts; Crescent City, Cali- 

 fornia; Gulf of Georgia; Britainlsland, Nova Scotia; Penikese Island, 

 Massachusetts; Key West, Florida; San Mateo, California; the Ber- 

 mudas; New York City; West Haven, Connecticut; Bloomington, Illi- 

 nois; Lawrence, Massachusetts; Woodside, Maryland; Grand Menan, 

 New Brunswick; Saginaw, Michigan; Lagonistas Creek, California; 

 Lake Maxinkuckee, Indiana; Freeport, Maine; Greenland; Newfound- 

 land; New York; Niagara, New York; San Francisco, California; San 

 Pedro, California; St. Paul Island; St. Croix; Ascension Island; Kam- 

 chatka; Iceland; Hawaii; Cape of Good Hope; all Europe; distribu- 

 tion world-wide. 



Found under dead leaves and stumps, under brick and boards; along 

 the shore; in greenhouses. 



Body ovate, not capable of being rolled up into a ball, and less than 

 twice as long as wide, 6 mm. : 10 mm. 



Head twice as wide as long, 2 mm. : 1 mm., with the anterior mar- 

 gin produced in three lobes, one median and two lateral lobes. The 

 median lobe is triangular, with apex obtuse; the lateral lobes are 

 rounded and large and extend as far as the median lobe. The eyes 

 are small, round, and composite, and are situated at the base of the 

 antero-lateral expansions. The first pair of antennas are rudimentary 

 and inconspicuous and are composed of three articles. The second pair 

 of antennas have the basal article short; the second is about one and a 

 half times as long as the first; the third is as long as the second; the 

 fourth is nearly twice as long as the third; the fifth is nearly twice as 



