ISOPODS OE^ NORTH AMERICA. 



885 



three. The epinioni of all the .seg-ments are consolidated with the 

 segments. The lateral margins are almost straight and continuous. 



The abdomen is composed of one segment, with lateral sutures at the 

 base, indicating another partly coalesced segment; it tapers to a narrow 

 extremity, the apex of which is emarginate. 



The legs are more or less alike in structure. 



SYNIDOTEA BICUSPIDA (Owen). 



Idotea hicuspida Owen, Crnstacea of the Blossom, 1839, p. 92, pi. xxvii, fig. 6. 

 Idotea pidchra Lockington, Proc. Cal. Acad. Sci., VII, 1877, p. 44. 

 Edotca bicuspida Miers, Jour. Linn. See. London, XVI, 1883, p. 66. 

 Sijnidotea bicuspida Sars, Crust. Norwegian North Atlantic Exp., 1885, p. 116, 



pi. X, figs. 24-26.— Benedict, Proc. Acad. Nat. Sci. Phila., 1897, pp. 



391-392.— Richardson, Proc. U. S. Nat. Mus., XXI, 1899, p. 848; Ann. 



Mag. Nat. Hist. (7), IV, 1899, p. 268; American Naturalist, XXXIV, 1900, p. 



228. 



Localities. — West coast of Alaska and Bering Sea; Kara Sea (Han- 

 sen). 



Dcjjt/i.—d^ to 81 fathoms, in mud, sand, and gravel; from sponges. 



Body ovate, about twice as long as wide, 12 mm. : 25 mm. Length of 

 abdomen equal to one-third the entire length of body, 8 mm.: 24 mm. 



Head with front produced on either side 

 of a median excavation in a wide border, 

 the lateral portion of which forms an an- 

 gle with the dorsal portion. Eyes large, 

 compound, and situated about the middle 

 of the head at the extreme lateral margin. 

 The tirst pair of antennae have the basal 

 article short and not dilated; the second 

 and fourth are about equal in length and 

 not longer than the tirst article; the third 

 is a little longer than any of the others. 

 The first pair of antenn:i> extend to the mid- 

 dle of the thirl peduncular article of the 

 second pair of antennae. The basal article 

 of the second antenna^ is inconspicuous 

 from a dorsal view; the second article is 

 about as long as the first; the third and 

 fourth are each about twice as long as the second; the fifth is 

 nearly as long as the third and fourth together. The tlagellum con- 

 sists of fifteen articles. The second antennte extend to the posterior 

 margin of the thii-d thoracic segment. The maxillipeds have a palp of 

 three articles. 



The segments of the thorax are subc^qual along the median dorsal 

 line. The first is pei-hap.s a little shorter. The epimcra of all the 

 segments are coalesced with the segments, with no indication of a 

 28589—05 25 



Fig. 424. — Synidotea bicvspida 

 (After Benedict), x 2. 



