II Richardson — Isopods of the Bermudas. 307 



which he identified as L. exotica, that they differed from the speci- 

 mens of L. exotica in his collection from Senegal in the thickness of 

 the tarsus, which was furnished with long, stiff hairs in the males. 

 However, he did not consider this a specific character ; it could only 

 be sufficient to distinguish a variety, for which he proposed the name 

 hirtitarsis. His specimens should undoubtedly be referred to Ligia 

 baudiniana, the characters of which, as a distinct species, near, 

 perhaps, but not identical with Ligia exotica, I shall endeavor to 

 point out. 



A comparison of male specimens of Ligia baudiniana and Ligia 

 exotica show the following points of difference : 



First, in the size and formation of the body, Ligia baudiniana 

 being the smaller species, with the body more compaet than in I. 

 exotica, which has the segments very loosely articulated. 



Second, in the length of the antennae, which in L. baudiniana do 

 not extend beyond the last segment of the thorax (which character 

 is constant, being true of all the specimens examined), while in L. 

 exotica the antennae reach the extremity of the body in all the speci- 

 mens examined. 



Third, in the length of the peduncle of the antennae, which in I. 

 baudiniana extend to the posterior margin of the second thoracic 

 segment, the last two joints being shorter than in L. exotica, the 

 peduncle of whose antennae reach the posterior margin of the third 

 thoracic segment. 



Fourth, in the character of the first pair of legs in the two species, 

 those of L. exotica (plate xl, figs. 62a, 62b,) having the propodus 

 furnished near the apex with a conspicuous process, oval and pro- 

 duced, the carpus and merus not being fringed with a thick row of 

 long stiff hairs, while those of L. baudiniana (fig. 61) have the pro- 

 podus simple, unarmed and without a conspicuous process, the carpus 

 and merus being fringed along the entire posterior margin with a 

 row of long stiff hairs. 



Fifth in the shape of the terminal segment of the body, the angle 

 in the middle of the posterior margin being more acutely produced 

 in L. exotica than in L. baudiniana, and the lateral angulations 

 being also much more produced. In the color of the two forms, L. 

 baudiniana being much lighter in color, the color extending to the 

 margins of the segments, while in L. exotica there is a colorless bor- 

 der on the lateral and posterior edges of all the segments. 



In the females of the two species the first pair of legs are simple. 

 The antennae are shorter than in the males, and the peduncle of the 



