no. 1701. 



NORTHWEST PACIFIC ISOPODS—RICHARDSOX. 



125 



Attached to one of the legs of /Ega symmetrica Richardson was a 

 parasite, the outline of which was more or less irregularly trans- 

 versely oval, with no traces of segmentation on the dorsal surface. 

 The body seems to be converted into a sac for carrying the eggs, 



Fig. 49. — Isopod parasite, 

 sal view. X 14i. 



Dor- 



Fig. 50. — Isopod parasite. Ven- 

 tral view. X 141. 



which fill the lateral portions and can be seen through the thin, 

 almost transparent integument. On the ventral side at the anterior 

 end is the oral opening, below which are the lamella? which bound 

 the opening into the marsupial cavity. Below these lamellae are two 

 small oval lamellae, one on either side. 



Type-specimen.— -Cat. No. 39524, U.S.N.M. 



ONISCOIDEA. 

 Family LIGYDID2E. 

 Genus LIGYDA Rafinesque. 



LIGYDA PALLASII (Brandt). 



Ligia pallasii Brandt, Bull. Soc. Imper. des Natur. de Moscou, vol. 6, 1833, 

 p. 172. 



Ligia dilatata Stimpson, Bost. Jour. Nat. Hist., vol. 6, 1857, p. 507, pi. 22, 

 fig. 8.— Smith, Report Progress Geol. Survey of Canada, 1880, p. 218. — Under- 

 wood, Bull. 111. State LaE. Nat Hist., vol. 2, 1886, p. 361. 



Ligia septentrionalis Lockington, Proc. Cal. Acad. Sci., vol. 7, 1877, pt. 1, p. 46. 



Ligia stimpsoni Miers, Proc. Zool. Soc. London, 1877, p. 671 (footnote). 



Ligia pallasii Budde-Lund, Crust. Isop. Terrestria, 1885, pp. 261-262. — Richard- 

 son, Proc. U. S. Nat. Mus., vol. 21, 1899, p. 866; Ann Mag. Nat. Hist. (7), vol. 

 4, 1899, p. 334; American Naturalist, vol. 34, 1900, p. 306; Harriinan Alaska 

 Expedition, Crust., vol. 10, 1904, p. 226; Proc. U. S. Nat. Mus., vol. 27, 1904, 

 p. 670. 



Ligyda pallasii Richardson, Bull. U. S. Nat. Mus., No. 54, 1905, pp. 682-684. 



Localities. — Attu Island; Nazan Bay, Atka. 

 Depth. — Shore. 



LIGYDA EXOTICA (Roux). 



Ligia exotica Roux, Crust. Medit, 1828, p. 3, pi. 13, fig. 9. — Budde-Lund, Crust. 

 Isop. Terrestria, 1885, pp. 266-268.— Richardson, Proc. U. S. Nat. Mus., 

 vol. 21, 1899, p. 866; Ann. Mag. Nat. Hist. (7), vol. 4, 1899, p. 335; American 

 Naturalist, vol. 34, 1900, p. 306 ; Proc. U. S. Nat. Mus., vol. 23, 1901, p. 575. 



