ISOPODS OK NORTH AMERICA. 



688 



FUi. 720.— LlGYKA I'ALLA.SII (Aktek ►STIMPSON). X Ij. 



Body obloiig'-ovate, nearly twice as lon^- as hroad. II iiiiii.:'20 inin. 

 Length of lU'opoda Iroin tij) of tei'iiiinal seonn-nt of Ixxly. )! luiii. 

 Length of body, inchiding ui'opoda. '2'-'> unii. Siii'face covered with 

 ndniite granid(\s. 



Head more than twice as wide as long, 2 nun. : 5 mm. Anterior mar- 

 gin widely rounded. Eyes large and round, composite, and situated 

 close to the lateral margins. 

 First pair of antennae incon- 

 spicuous and rudimentary 

 and composed of two short, 

 subequal articles and a mi- 

 luite terminal article. The 

 first antemue extend onh' to 

 the end of the first article of 

 the peduncle of the second 

 antenniv. The first two arti- 

 cles of the second pair of an- 

 tenna? are equal in length; 

 the third is nearly twice as 

 long as the second; the 

 fourth is one and a half times 

 longer than the third; the 

 fifth is one and a half times 

 longer than the fourth. The flagellum is composed of twelve articles. 

 The second pair of antenna? extend to the middle of the fourth thoracic 

 segment when retracted. The maxilliped has a palp of five articles. 



The first four segments of the thorax are subequal; the last three 

 are somewhat shorter in the median dorsal line. The lateral portions 



of the last three segments extend 

 downward. The epimera of all the 

 segments are broad plates, occupying 

 the whole of the lateral margins of 

 the segments and indicated by dis- 

 tinct lines. 



The abdomen is as wide as the tho- 

 rax, the lateral parts of the third seg- 

 ment extending as far as the lateral 

 parts of the seventh thoracic seg- 

 ment. The lateral parts of the first 

 two segments of the abdomen are not 

 developed; those of the last four segments are well developed and 

 have the posterior angles produced downward. The lateral parts are 

 not separated off from the dorsal portion of the segments. On the 

 lateral parts of the third, fourth, and fifth segments are distinct carina? 

 extending obliquel}^ from the middle of the segment to the posterior 



Fl(i.727.— LiGYDA PALLASII. «, Maxillipe 

 X 20^. h, First leg of male, x 7i. 



