1SOPODS OF NORTH AMERICA. 



681 



LIGYDA OCCIDENTALIS (Dana). 



Ligiu occidental!* DANA, U. S. Expl. Exp., Crust., XIV, 1853, p. 742, pi. XLIX, 

 fig. 7; Proc. Acad. Nat. Sci. Phila., VII, 1854-55, p. 176. STIMPSON, Boat, 

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

 1877, p. 116. BUDDE-LUND, Crust. Isop. Terrestria, 1885, p. 264. UNDER- 

 WOOD, Bull. 111. State Lab. Nat. Hist., II, 1886, p. 360. 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 Diego; Santa Cruz 

 Island, California; Sacra- 

 mento River; Monterey 

 Bay ; St. Marguerita Island, 

 Lower California; Sausa- 

 lito, California; San Barto- 

 lome Ba}r, Lower Califor- 

 nia; Farallones, California 

 (J. Lindahl); San Jose Is- 

 land, Gulf of California. 



Body oblong-ovate, a lit- 

 tle more than twice as long 

 as broad, 12 mm. : 26 mm. 

 Uropoda 8 mm. long, or less 

 than one-third the length of 

 the body. Entire length of 

 body with uropoda 34 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 by 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 1 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 twent\ T -nine articles, and extends to the 

 posterior margin of the sixth thoracic segment. The peduncle 



FIG. 724. LIGYDA OCCIDENTALIS (AFTER DANA), a, PE- 

 DUNCLE OF SECOND ANTENNA. 6, ABDOMEN AND URO- 

 PODA. c, JOINTS OF FLAGELLUM. d, TIP OF FLAGELLUM. 

 e, FIRST LEG OF MALE. 



