ISOPODS OF NORTH AMERICA. 367 



anteriorly at the sides to surround the posterior portion of the head. 

 All the segments are equal in length. The epimeron of the second seg- 

 ment extends half the length of the lateral margin; it is broader at its 

 anterior end than at its posterior end. The epimera of the third and 

 fourth segments occupy the anterior two-thirds of the lateral margin. 

 The epimeron of the fifth segment extends almost the entire length of 

 the lateral margin of the segment. The epimera of the sixth and seventh 

 segments reach the posterior extremity of the lateral margin, and are 

 broader at the posterior end than at the anterior end. The legs are all 

 similar. The inferior margin of the merus, carpus, and propodus is 

 densely furnished with hairs. 



The abdomen has two short segments and one long terminal one 

 with lateral rudiments of another partly coalesced segment. The 

 terminal segment tapers to about the middle, and from that point to 

 the post-lateral angles, the sides are nearly parallel. The lateral angles 

 are rounded. The posterior margin is produced in an obtuse median 

 process, triangulate in shape, and extending some distance beyond the 

 lateral angles. The apex of this process is rounded. 



IDOTHEA PHOSPHOREA Harger. 



Idotea phosphorea HARGER with Verrill, Report U. S. Commissioner of Fish and 

 Fisheries, Pt. 1, 1873, p. 569 (275); p. 316 (22). VERRILL, Am. Jour. Sci., 

 1874, pp. 43, 45, 131; Proc. Amer. Assoc., 1874, 

 pp. 362, 367, 369. WHITEAVES, Am. Jour. Sci., 

 VII, 1874, p. 218. HARGER, Proc. U. S. Nat. 

 Mus , II, 1879, p. 160; Report U. S. Commis- 

 sioner of Fish and Fisheries, Pt. 6, 1880, pp. 347- 

 348, pi. v, figs. 27-29. 



Idotea marina var. phosphorea MIERS, Journ. Linn. 

 Soc. London, Zoology, XVI, 1883, pp. 31-32. 



Idotea phosphorea RICHARDSON, American Naturalist, 

 XXXIV, 1900, p. 227; Proc. U. S. Nat. Mus., 

 XXIII, 1901, p. 541. PAULMIER, Bull. New York 

 State Museum, 1905, pp. 176-177. 



Localities. Coast of New England to Halifax, 

 Nova Scotia, and the Gulf of St. Lawrence; 

 Runmaro, Stockholms Skargard (J. Lindahl). 



Depth. Surface to 18 fathoms. Found FIG. sas. IDOTHEA PHOS- 

 among seaweed: part of contents of haddock CHOREA (AFTER HAR- 



, GER). X 2. 



stomach. 



Body oblong-ovate, three times longer than broad, 7 mm. : 21 mm. 

 Length of abdomen a little more than one-third the entire length of 

 the body, 8 mm. : 21 mm. 



Head broader than long, with the anterior margin straight on either 

 side of a slight median excavation. The eyes are moderately large, 

 round, compound in structure, and placed just in front of the median 

 transverse line at the extreme lateral margin. Basal article of first 



