ORDER ISOPODA. 225 



In the others and all terrestrial, the lateral antennae pre- 

 sent at most but eight articulations, whose proportions towards 

 the extremity diminish gradually, without any of them ap- 

 pearing to be divided or composed. 



Here the appendages, or posterior stylets, advance beyond 

 the last segment. The body does not contract itself, or at 

 least very imperfectly, into a ball. 



Philoscia, Lat., 



Have the lateral antennae divided into eight articulations, and 

 uncovered at their base. The four posterior appendages are 

 almost equal, {Oniscus Sylvestris, Fab.) 



Oniscus (proper) Lin., Wood-lice, Vulg. 



Have also eight articulations to the lateral antennae, but their 

 base is curved, and the two exterior appendages of the end of 

 the tail are much larger than the two interior. {Oniscus Mu- 

 rarius, Fab.) 



PORCELLIO, Lat., 



Are distinguished from oniscus by the number of articulations 

 of the lateral antennae, which is only seven. [Oniscus asellus, 

 Cuv.) 



Armadillo. 



The posterior appendages of the body make no projection. 

 The last segment is triangular ; a small lamina, in the form of 

 an invei'ted triangle, or more wide, and truncated at the end, 

 formed by the last articulation of the lateral appendages, fills, 

 on each side, the vacancy comprized between this segment 

 and the preceding. The lateral antennae have but seven arti- 

 culations. The upper subcaudal scales have a range of small 

 holes. (Oniscus Armadillo, Lin ) 



VOL. XIII. 



