ISOPODS OF NORTH AMERICA. 



681 



LIGYDA OCCIDENTALIS (Dana). 



Liyia occidentulh Dana, IT. S. Kxpl. Kxp., Crust., XIV, l.Soo, p. 74L', pi. xlix, 

 fig. 7; Proc. Acad. Nat. 8ci. Phila., VII, 1854-55, j). 17().— Sti.mpsox, Bost. 

 Jour. Nat. Hist., VI, 1857, p. 506. — Harforo, Proc. Cal. Acad. Sci., VII, 

 1877, p. 116. — Bi^DDE-LuND, Crust. Isop. Terrestria, 1885, p. 264. — Under- 

 wood, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 860.— 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. — California; San Francisco Bay: San Dieo-o; Santa Cruz 

 Island, California; Sacra- 

 mento River; Monterey 

 Bay; St. Marg-uerita Island, 

 Lower California; Saiisa- 

 lito, California; San Barto- 

 lonie Ba3% Lower Califoi-- 

 nia; Farallones, California 

 (J. Lindahl); San Jose Ls- 

 land, (xulf of California. 



Body oblong-ovate, a lit- 

 tle more than twice as long 

 as broad, 12 mm. : 26 nmi. 

 Uropoda 8 mm. long, or less 

 than one-third the length of 

 the body. Entire length of 

 body with uropoda 31 mm. 



Head about twice as wide 

 as long, 2^ mm. : .5^ mm., 

 with the anterior margin 

 widely rounded. Eyes 

 large, composite, elongate, 

 and separated in front b}" a 

 distance equal to the length 

 of one eye, 2 mm. First 

 pair of antennae minute, in- 

 conspicuous. Second pair 

 with the first two articles 

 short and subequal; third 

 article li mm. long or as 

 long as the first two articles 

 together; fourth article 3 

 mm. long, twice as long as 

 the third article; fifth arti- 

 cle 5 mm. in length. The 



flagellum is composed of twenty-nine articles, and extends to the 

 posterior nrargin of the sixth thoracic segment. The peduncle 



rac?C5:r 



Fig. 724.— LlGYDA OCCIDENTALIS (AFTER DaNA). a, PE- 

 DUNCLE OF SECOND antenna, b, ABDOMEN AND URO- 



roDA. c, Joints of flagellum. d. Tip of flagellum. 

 r, First leg of male. 



