20 Mr. Lubbock on 



three strong, finely serrated hairs. In tlie male, tlie joints of 

 these five segments are so indistinct, that the organ would be de- 

 scribed as three-jointed. 



First pr. natatory legs, '017 in length. The rami in the female 

 are two and one-jointed. Those of the male are three-jointed. 

 They are not spinous, but the margins are partly fringed with 

 delicate hairs. 



The fourth pair ofnatatories is much larger, and is similar in the 

 two sexes. It is '03 inch in length, and the rami are both three- 

 jointed. There is a ciliated hair at the apex of each of the basal 

 segments, and the terminal segments have respectively four and 

 five large, ciliated hairs. 



Theffth pair of legs of the male are slender, and so long as to 

 reach to the front of the cephalothorax when they are turned for- 

 wards. The shorter leg of the two consists of four segments, of 

 which the second apparently represents the second basal seg- 

 ment of the natatory legs, and like it bears two branches, the 

 inner one of which is as long as the first segment of the outer 

 branch. The apical segment is long and gradually tapering. The 

 longer leg resembles the shorter one in general appearance, but 

 the inner branch is rudimentary, and the third segment bears at 

 the apex a cylindrical appendage, swollen at the ends, and armed 

 along the edges with a row of teeth. 



I do not understand how these legs are used. 



Total length 'IS inch. 



This species much resembles E. diadema of Dana, from which it 

 differs chiefly — 



1st, in having the angles of the head rounded off; 

 2nd, in the size of the maxillipeds ; and 

 3rd, in the structure of the fifth pair of legs of the female. 

 It seems very common, but the females are much more nume- 

 rous than the males. Dr. Sutherland found it in the Atlantic, 

 from 31° 50' N. Lat, to 3° S. Lat., and from 26° to 18° 30' W. 

 Long. 



Some of the females had from five to eleven eggs, and several 

 had a spermatic tube attached to the abdomen ; the time of year 

 being from the 9th of August to the 9ih of September. 

 PI. VIII. 



Euchceta Suthcrlandii, n. sp. 



Fceminae. — Cephalothorax nudus, 5-articulatus, postice obtusus, 

 capite bene arcuato sed non angulato. Antennae anticae cor- 

 pore paulo breviores, setas E. communi fere similes, seta pos- 



