ONISCID^. 439 



Family— ONISCID^. 



These animals are further distinguished by having the 

 anterior pair of antennae almost rudimental, so that they 

 appear to possess only one pair of these organs. The 

 tail is composed of six distinct segments ; but the ter- 

 minal joint, instead of being of large size, and formed 

 into a shield-like plate, is here small, and sometimes 

 almost rudimental. The legs are only formed for walking, 

 and the mandibles are destitute of the lateral articulated 

 appendage resembling a three-jointed palpus. 



The species for the most part are of comparatively 

 small size, and are indiscriminately known under the 

 common names of wood-lice, hog-lice, carpenters, &c. 

 With the exception of the species of Ligia (which com- 

 prises the largest individuals of the family, and which are 

 found in rocky places on the shores of the ocean in 

 various parts of the world), the Oniscidse are inland 

 creatures. Of fourteen species described by Professor 

 Kinahan in his memoir on this family, read at the British 

 Association in 1857, and published in the " Dublin 

 Natural History Review," vol. iv., he states that all, 

 except two (one a marine species), had been found by 

 him in a garden not sixty yards square, and nearly all 

 in abundance. 



Several of the species which inhabit caves and sub- 

 terranean situations are destitute of eyes. This is the 

 case with Titanethes albus, described and admirably illus- 

 trated by Schiodte in his memoir on the cave-animals 

 — " Specimen Faunae Subterranese," — published in the 

 '' Transactions of the Royal Society of Denmark," 5th 



