ISOPODS OF NORTH AMERICA. 619 



the uropoda extends almo.st to the extremity of the posterior angle of 

 the lateral part of the fifth abdotninal seg'nient, which is a little shorter 

 than the tip of the apical process of the sixth segment. The inner 

 branch is 1 mm. U)no- jind is partly concealed hy the apical process of 

 the sixth abdominal segment: it extends to the middle of the outer 

 branch. The outer l)ranch is 1 mm. long-, and extends about two- 

 thirds of its length beyond the apical process of the sixth at)d()minal 

 segment. 



All the legs are ambulatory in structure. 



In color it is a dark brown with three longitudinal lines of light 

 yellow, one median and one on either side at the place of union of the 

 epimera with the segments. Between the median liiK^ of light yellow 

 and the lateral lines are wavy lines of light 3'ellow on the ))rown color, 

 giving it a broken, mottled effect. 



The surface of the body is covered with low granules. 



PORCELLIO SPINICORNIS Say. 



PorceUio spin icornis Say, Jour. Ac. Nat. Sci. Phila., J, LSIS, pp. 431, 432. 

 Porcellio pictus Bratsidt and Ratzebueg, Med. Zool., II, 1830-1834, p. 78, pi. xii, 



figs. 5, 5e, 5f. 

 PorcelUu melanocephalus Koch, Deiitschl. Crust., 1835-1844, \). 28. 

 {?) Porcellio spinicornis De Kay, Zool. New York, Pt. 6, 1844, p. 51. 

 Porcellio mixtus Fitch, Rep. noxious ins., 1856, p. 120. 

 Porcellio pictusKiy AH A-N, Nat. Hist, rev., IV, 1857, p. 278. — Bate and Westwood, 



Brit. Sess. Crust., II, 1868, p. 480.— Budde-Lund, Nat. Tidsskr. (3), YII, 



1870, p. 239; Crust. Isop. Terrestria, 1885, pp. 123-125.— G. O. Sars, Crust. 



of Norway, II, 1899, pp. 177, 178, pi. lxxviii, fig. 1.— Stoller, 54th Report 



New York State Museum, 1902, p. 213. 



Localities. — North America, at New York; Niagara; Goshen, Con- 

 necticut; also Sweden; Denmark; Germany; Britain; France; Hun- 

 gar \'; Russia; coast of Norway. 



Found in the crevices of rocks and on shady limestone ledges. 

 (Stoller. ) 



Bodv nearly twice as long as wide, 7 mm. : 13 mm. 



Head twice as wide as long, li mm. : -3 mm., with the front pro- 

 duced in three lobes, the antero-lateral lobes being large and 

 rounded, the median lobe wide but short and almost truncate on its 

 anterior margin. The eyes are small, oval, composite, and situated at 

 the base of the antero-lateral lobes. The first pair of antenna? are 

 rudimentary and inconspicuous. The basal article of the second pair of 

 antenna? is short; the second and third are subequal and each is twice 

 as long as the first; the fourth is one and a half times as long as the 

 third; the fifth is one and a lialf times longer than the fourth. The 

 flagellum is composed of two articles, the first of which is one and a 

 half times longer than the second. The second antenna^ extend to the 

 posterior margin of the third thoracic segment. The second article 



