ISOPODS OF NORTH AMERICA. 685 



Ligia onisci'/es BKKHISSOX, Mt'm. Soc. Linn. Calv., 1825, p. 259. 



Ligia oceanica BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 259-2H1. SAKS, 

 Crust. Norway, II, 1899, pp. 156-157, pi. LXX. RICHARDSON, American 

 Naturalist, XXXIV, 1900, p. 306; Proc. IT. S. Nat. Mus., XXIII, 1901, p. 574. 



Localities. Off Newport, Rhode Island; North Sea; Baltic Sea; 

 Kattegat Sea; Norway; Faroe Islands; coast of Germany; Belgium; 

 Great Britain; France; Spain; Mediterranean Sea; west shore of 

 Helgoland. 



Body oblong-ovate, a little over twice as long as wide, 8 mm.: IT 

 mm. Length of uropoda from tip of terminal segment of body equal 

 to 5 mm. Length of body with uropoda 22-mm. Surface covered 

 with minute granules. 



Head twice as wide as long, 2 mm. : 4 mm. Anterior margin widely 

 rounded. Eyes large, round, composite, and situated at the extreme 

 lateral margins. The first pair of antennae are incon- 

 spicuous and rudimentary; they are each composed of 

 two articles and a minute terminal one, and reach to 

 the end of the basal article of the second pair of an- 

 tennae. The basal article of the second antennae is 

 veiy short; the second and third are subequal and each 

 is twice as long as the first; the fourth is twice as long- 

 as the third; the fifth is one and a half times longer 

 than the fourth. The flagellum consists of thirteen 

 articles. When retracted, the second antennas extend 

 to the posterior margin of the fourth thoracic seg- 

 ment. The maxilliped has a palp of five articles. 



The first six segments of the thorax are subequal; FIG. 729. LK.JYUA 



11 mi 1 1 ' ' OCEANICA. MAX- 



the seventh is a little shorter. The lateral parts of ILLIPED. x 2-{. 



the last four segments extend somewhat downward. 



The epimera of all the segments are indicated by distinct lines. They 



are broad plates and occupy the whole of the lateral margins of the 



segments. 



The abdomen is not narrower than the thorax, the third segment 

 being as wide as the last thoracic segment. The lateral parts of the 

 first two segments are not developed. The lateral parts of the other 

 segments are not separated off from the dorsal portion. The segments 

 increase gradually in length from the first to the fifth. The sixth or 

 terminal segment has the middle part of the posterior extremity regu- 

 larly rounded. The lateral angles are acute, and do not extend quite 

 to the tip of the terminal segment. The basal segment or peduncle 

 of the uropoda is 1 mm. in length from the extremity or tip of the 

 middle portion of the abdomen. The branches are equal in length, 

 and are four times as long as the basal segment. The inner branch is 

 furnished with a short bristle 1 mm. in length. 



The legs are all ambulatory. 



