ISOPODS OF NORTH AMERICA. <)95 



Localities. North America; also Sweden, Denmark, Germany, 

 France, Great Britain, Spain, Algeria, and Norway. 



Body oblong-ovate, three times as long as wide, 1 mm. : 3 mm. 



Head wider than long, with the anterior margin produced in a 

 widely rounded, obtuse median lobe. There are no antero-lateral 

 lobes. The eyes are small, round, composite, and situated in the 

 antero-lateral angles of the head. The first pair of antennae are rudi- 

 mentary and inconspicuous. The first three articles of the second 

 antennae are short, the first two being subequal, the third, one and a 

 half times longer than either of the others; the fourth and fifth are 

 subequal and each is one and a half times longer than the third. The 

 flagelluin is composed of four or five ill-defined articles. The maxil- 

 liped has a palp of two articles. The palp of the mandibles is 

 wanting. 



The segments of the thorax are subequal. The epimera are not 

 separated oif on any of the segments. 



The abdomen is abruptly narrower than the thorax. The first two 

 segments have the lateral parts covered by the seventh thoracic seg- 

 ment. The sixth, or terminal, segment is wide posteriorly, with the 

 post-lateral angles rounded and a slight emargination in the middle of 

 the posterior margin. The basal article of the uropoda or the peduncle 

 extends as far as the posterior margin of the terminal segment. The 

 inner branch is more slender and is a little shorter than the outer 

 branch. Both branches extend 

 some distance beyond the abdo- 

 men. All the legs are ambula- 

 tory. 



TRICHONISCUS PAPILLICOR- 

 NIS Richardson. 



Trichoniscus papillicornis RICHARD- 

 SON, Harriman Alaska Exp. 

 Crust., X, pp. 213-230; Proc. 

 U. S. Nat. Mus., XXVII, 1904, 

 pp. 670-671. 

 Locality. Seldovia, Cook In- FIG - 734.-TBicHoxiscu8 PAFILLICORMS. HEAD AND 



FIRST THORACIC SEGMENT. X 41. 



let, Alaska. 



Body covered with low tubercles. Color light brown. 



Head with sides produced at the antero-lateral angles in large lobes; 

 front triangularly produced with a slight emargination at the apex of 

 the triangle. E3 r es situated on the lateral margins at the base of the 

 antero-lateral lobes; they are small and black and apparently simple 

 in structure. The peduncle of the antennae consists of five stout joints, 

 the last three of which have the inner margins beset with numerous 

 strong tubercular-like papillae, each surmounted with a tuft of short 



