ISOPODS OF NORTH AMERICA. 



297 



near Wrangell, Alaska; Puget Sound; Kyska Harbor, Alaska; Monte- 

 rey Bay, California; Middleton Island; LInalaska; Sitka, Alaska; 

 Bering Island; Sanborn Harbor, 

 Nagai Island; Saginaw Bay, 

 Alaska: North Grebnitzky. 



Found on beach at low tide; 

 1<)-1'2 fathoms, in gravel, sand, 

 and stones; rocky beach under 

 stones; in mud. 



Body ovate, twice as long as 

 wide, 4 mm. : 8 mm. 



Head three times as wide as 

 long, 1 mm.: 3 mm., with the 

 frontal margin bi-sinuate, or ex- 

 cavate on either side of a small 

 median point. Eyes small, round, 

 composite, and placed in the 

 post-lateral angles of the head. 

 The first antennae have the basal 

 article large; the second article 



is half as long as the first; the third is one and a half times longer 

 than the second. The flagellum is composed of thirteen articles. 

 The first antenna? extend to the posterior margin of the head. The 

 second antenna 3 have the basal article very short and almost inconspicu- 

 ous; the second article is about three times as long as the first; the third 



FIG. 315. EXOSPH.EROMA OREGONENSIS (AFTER 



DANA), a, SECOND ANTENNA, b, GENERAL FIGURE. 

 c, ABDOMEN (UNDERSIDE). (ALL ENLARGED.) 



FlG. 316. EXOSPH.EROMA OREGONENSIS. a, MAXILLIPED. X 51|. 6, MANDIBLE, PALP REMOVED. 



x 51 f. <*, MANDIBLE WITH PALP, x 61 J. d, FRONTAL LAMINA AND CLYPEUS. x 61|. 



is about as long as the second; the fourth is nearly twice as long as the 

 third; the fifth is as long as the fourth. The flagellum is composed of 

 thirteen articles. The second antennae extend to the posterior mar- 

 gin of the second thoracic segment. The maxilliped has a palp of five 

 articles. Mandibles with a three-jointed palp. 



