682 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



of the second antenna? extends to the posterior margin of the second 

 thoracic segment. The palp of the maxillipeds is composed of five 

 articles. 



The first four seg-ments of the thorax are subequal and each is about 

 ^ mm. longer than any of the last three, which are subequal. The 

 epimera are perfectly united with the segments, faint 

 lines of depression marking the place of coalescence. 



All six segments of the abdomen are distinct, the first 

 two being a little shorter than the three following, and 

 having the lateral parts covered by the seventh thoracic 

 segment. The third, fourth, and fifth segments gradu- 

 ally increase in length, and have the post-lateral angles 

 produced backward in acute processes, which have a 

 faintly marked carina crossing them obliquel3\ The 

 Fig. 725.— LiG YD A terminal segment has the posterior margin triangularly 

 First leg (last produced in an obtuse point. Between this and the 

 TWO JOINTS). V lateral angles, which are acute, are two small points. 

 The peduncle of the uropoda is 3 mm. long. The 

 branches are 5 mm. in length and subequal. 



The legs are all ambulatory, and have the dactylus bi-unguiculate. 

 The first pair in the male have the propodus armed at the distal end 

 on the inner margin with a conspicuous triangular process, similar to 

 that in Z. exotica. 



Entire surface of body covered with small granules. 



LIGYDA PALLASII (Brandt.) 



Ligia pallasii Brandt, Bull. Soc. Imp^r des Natur. de Moscou, VI, 1833, p. 172. 

 Ligia diZototo Stimpson, Bost. Jour. Nat. Hist., VI, 1857, p. 507, pi. xxii, fig. 8. 

 Ligia septentrionalis Lockington, Proc. Cal. Acad. Sci., VII, 1877, Pt. 1, p. 46. 

 Ligia slimpsoni Miers, Proc. Zool. Soc. London, 1877, p. 671 (foot note). 

 Ligia dilatata Smith, Report Progress Geo!. Survey of Canada, 1880, p. 218. 

 Ligia jmllasii BvoDE-ljvm), Crust. Isop. Terrestria, 1885, pp. 261-262. 

 Ligia dilatata Underwood, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 360. 

 IJgia pallasii Underwood, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 361.— 



Richardson, Proc. U. S. Nat. Mus., XXI, 1899, p. 866; Ann. Mag. Nat. 



Hist. (7), IV, 1899, p. 334; American Naturalist, XXXIV, 1900, p. 306; 



Harriman Alaska Exp., Crust., X, 1904, p. 226; Proc. U. S. Nat. Mus., 



XXVII, 1904, p. 670. 



Localities. — llnalaska; Sitka; Wrangel, Alaska; Tanager; Chica 

 Island, Akutan Pass; Lighthouse Rocks, Alaska; Ward Cove, Revilla- 

 gigedo Island, Alaska; Ky ska Harbor; Aleutian Islands; Nazan Bay, 

 Atka; Victoria, Vancouver Island; Puget Sound; Port Townsend, 

 Washington; California; Lowe Inlet, British Columl)ia; Washington 

 Territory; Lagonistas Creek, California; Farallones, Calif oi'nia; Cape 

 Mendocino, California. Found on rock beach, under stones. 



