TOMOCERUS. 139 



on each side of it. The mandibles have, respectively, 

 four and five teeth. The processes at the end of 

 the maxillge are not exactly like those of T. jplumhea. 



The anterior feet have the usual tenent hair, and 

 on the under side of the large claw, five or six small 

 teeth ; the lesser claw is lanceolate in form, but with 

 the lower margin straighter than the upper one, and 

 has a single, very minute tooth on the upper side. The 

 second and third pairs of feet much resemble the first ; 

 but the small spine on the lesser claw of the third pair 

 is rudimentary or altogether absent. On the basal 

 part of the caudal appendage are, as in T. phmihea, 

 nine black spines. In that species, however, they are 

 simple and short, while in the present they are much 

 longer ; the four first form a somewhat curved line ; 

 the remaining five are arranged in a straight row, and 

 have small processes at the side ; the apical spine and 

 the penultimate are the largest. 



The form and arrangement of these spines, and the 

 structure of the feet, satisfactorily distinguish this 

 species from the preceding. If in T. minor, which is 

 smaller than T. jjlumbea, these caudal spines had been 

 smaller than in that species, and the spines on the feet 

 had been less numerous, we might well have supposed 

 that these differences depended on age, and were 

 therefore of no value as specific characters. I was, 

 indeed, for a long time disposed to consider T. minor 

 as being merely the young stage of the larger T.pliim- 

 hea ; but the large specimens are comparatively so rare, 

 that, for this reason alone, such an opinion seemed to 

 me untenable. This is, I think, confirmed by the 

 structure of the feet and of the caudal appendage. 



Tomoceriis niger, Bourlet. 



Macrotoma nigra, Bourlet. Mem. Soc. Roy. Lille, 1839. 



— ferruginosa, „ „ „ „ 



Tomocerus ccler, Nicolet. Mem. Soc. Helv., 1842. 

 Macrotoma celer, Gervais. Ins. Apteres, vol. iii. 



