ISOPODS OF NORTH AMERICA. 



3(>3 



Wales; Borneo; ott' Cape Nej^ro; Latitude Cove, Patagonia; -lu miles 

 south of Cape Sable. 



Deptlt. — Surface to 1>1 fathoms. 



From floating fucus. 



Body oblong-ovate, al)out two and one-fourth times as long as wide, 

 8 mm. :18 mm. 



Abdomen a little morc^ than two-tifths the entii'e length of body, 

 8 mm. : 18 mm. 



Head wider than long, with anterior margin slightly excavate. Tln^ 

 posterior portion is somewhat wider than the anterior portion. Eyes 

 large and round, compound in structure, and situated at the extreme 

 lateral mai'gin. First pair of antenna' with the l)asal article not 

 enlarged, the tirst and second articles being about equal in length and 

 width. The third and fourth articles are somewhat longer than either 

 the tirst or the second article. The 

 tirst antenna? extend to the end of the 

 second article of the peduncle of 

 the second pair of antenna?. The 

 first article of the second pair of an- 

 tennte is very short; the second and 

 third are su])equal; the fourth is one 

 and a halt' times longer than the third, 

 and the fifth is twice as long as the 

 third. The flagellum is composed of 

 eight articles and reaches when re- 

 tracted to the anterior margin of the 

 third thoracic segment. The maxilli- 

 ped has a palp of four articles. 



The segments of the thorax are sub- 

 equal. The first segment extends a 



little beyond the lateral margins of the head on either side. The 

 lateral portions of this segment and of those following are curved out- 

 ward and somewhat upward, forming an angle with the portion of the 

 segment to which it is adjacent. The epimera of all the segments, 

 from the second to the seventh, inclusive, extend the entire length of 

 the segment. The epimera are large and very wide, increasing in 

 width to the seventh, which is wider than long. 



The legs are all more or less alike in character. The free margins 

 of all the joints and the inferior margin of the propodus is furnished 

 with hairs. The abdomen has two short segments and one long ter- 

 minal one, with lateral rudiments at its base of another partly coalesced 

 segment. The terminal segment has the sides converging slightly to 

 a truncate extremit}'. 



Fig. 393. — Idothea metallica. o, Maxilli- 

 ped. x 27|. 6, flkst antenna. x 15^. 



