ISOPOD8 OF NORTH AMERICA. 89 



Body oblong-ovate, two and a half times longer than broad, 4 mm. : 

 10 mm. 



Head two and a half times wider than long, 1 mm. : 2 mm. Front 

 produced in a long median point which separates the basal articles of 

 the first pair of antennae and meets and is coalesced with the anterior 

 end of the frontal lamina, which arches over the second antennae and 

 forms a dorsal continuation of the median frontal process extending 

 1 mm. beyond the frontal margin of the head. The eyes are small, 

 round, composite, and situated in the antero-lateral angles of the 

 head. The first pair of antennae have the first two articles short and 

 subequal; the third article is half as long and narrower than either of 

 the other two. The flagellum is composed of thirteen articles. The 

 first pair of antennae extend almost to the posterior margin of the first 

 thoracic segment. The second antennas have the peduncle apparentlv 

 composed of only four articles; the first article is short and almost 

 inconspicuous; the second and third articles are subequal; the fourth 

 and fifth are also subequal and each is a little longer than the third. 

 The flagellum is composed of twenty- 

 three articles. The second antenna; ex- 

 tend to the posterior margin of the third 

 thoracic segment. The first nine or ten 

 articles of the flagellum have a tuft of 

 hairs on the outer margin. The interan- 

 tennal plate or frontal lamina is wide and 

 conspicuous and arches over the second 

 pair of antennae meeting the anterior end *te.m CIBOLAHA HAYAMA. SECOND 



, rr.i ANTENNA. X 2<H- 



or the frontal process. The clypeus has 



the anterior end produced over the posterior end of the frontal lamina 

 and extends out from it. Maxilliped composed of seven articles. 

 The mandible has a palp of three articles. 



The first, fourth, and fifth segments of the thorax are a little longer 

 than any of the others. The epimera of all the segments, with the 

 exception of the first, are distinct. In the second and third segments 

 they are narrow, increasing in width from those of the fourth to the 

 seventh segments. The postero-lateral angles of the last three are 

 acute and produced beyond the posterior margins of the segments. 

 All the epimera are crossed by an oblique carina. 



The first segment of the abdomen is almost entirely covered by the 

 seventh thoracic segment. The fifth segment is as wide as the fourth, 

 and is not covered at the sides by the lateral parts of the preceding 

 segment. The sixth or terminal segment is rounded posteriorly. The 

 inner branch of the uropoda is as long as the terminal segment of the 

 body, and is slightly emarginate on its external margin. The outer 

 branch is longer than the inner branch and is rounded posteriorly. 

 The peduncle extends as far as the emargination on the exterior 

 margin of the inner branch. Both branches are beset with spines. 



