ARCTURUS GRAC1LIS. 



ISOPODA. 

 NORMALIA. 



373 



ARCTURID^E. 



ARCTURUS GRACILIS. 



Specific character. Very slender, quite smooth, and destitute of tubercles ; 

 the upper antennas rather shorter than the first three joints of the lower ; the 

 fourth segment of the body linear-cylindric, and not tubercled. 



Length, seven lines. 

 Leachia yracilis. 



Arcturus yr. 



H. GOODSIR, Edinb. New Phil. Journ. xxxi. p. 310, pL 6, 



f. 4. 

 WHITE, Cat. Brit. Crust, p. 64. Pop. Hist. Brit. Crust. 



p. 222. 



IN this species the body is very slender and quite 

 smooth, without the tubercles, which are found in all 

 the other species. The plate which covers the base of 

 the antennae projects, and is rounded anteriorly. The 

 superior antennae are almost as long as the first three 

 joints of the inferior, the first joint being globular, the 

 second and third linear, each as long as the first ; the fla- 

 gellum is equal in length, or longer, than the peduncle, 

 and the last articulation is minute and linear. The 

 inferior antennae are as long as the body, with the first 

 joint obsolete, the second slightly clavate, and the flagel- 

 lum strongly pectinated on their inferior edges. Both 

 pairs of antennae have a few bristles scattered over them. 

 The body is quite smooth, except a few scattered punc- 

 tures. The fourth segment is linear, cylindrical, and not 



