546 MERISTIC VARIATION. [part i. 



849. Chlaenius holosericus (Carab.): left anterior tibia enlarged and 

 dividing close to base into two branches of similar form and length 

 [curving towards each other], both equally furnished with hairs and 

 bearing spines characteristic of the species. Anterior branch bears a 

 complete tarsus like that of a leg of the other side, but posterior branch 

 bears only one tarsal joint. Camerano, Atti Ac. Sci. Torino, 1878, 

 Xiv. fig. 

 *850. Brachinus crepitans (Carab.) : 3rd joint of right posterior tarsus 

 enlarged ; 4th joint divides to form two apices (Fig. 205), each bearing 

 separate 5th joint in same horizontal plane. Each of these has a pair 



Fig. 205. Eight hind foot of Brachinus crepitans, No. 850. A, anterior. 

 P, posterior. E, the supposed normal right apex. (In Eouen Mus.) 



of claws curving ventralwards. The two apical joints are not identical, 

 the anterior being the shorter and continuing the general direction of 

 the tarsus. I could not determine the symmetry. When examined by 

 me the specimen was intact, but in cleaning it I broke this abnormal 

 leg. First described by Mocquerys, Col. anorm., 1880, p. 63, fig. 



The two following cases differ from the rest in that the extra 

 leg arose from the body separately from the normal leg. Among 

 the cases of extra limbs in Secondary Symmetry were a few in 

 which the coxa of the extra limbs was in the same socket as 

 the coxa of a normal leg, though not united to it ; but in the 

 first, and perhaps in both of the two cases that follow, the extra 

 leg was wholly separate. The first case, No. 851, is the only one of 

 the kind that I have seen. 



'851. Tenthredo ignobilis (Tenthred., Sawiiy) : extra leg arising from 

 prothorax, on the left side of the body, at some distance behind the 

 proper left anterior leg. Behind the anterior legs the prothorax of a 

 normal specimen presents ventrally an elevation on each side of the 

 middle line ; the point of origin of the extra leg is about halfway 

 between this elevation and the socket of the coxa of the normal left 

 anterior leg. The specimen had been a good deal injured by being 

 pinned very nearly through the point of origin of the extra leg, and on 

 relaxing the specimen and attempting to restore the parts to their 

 former positions I unfortunately broke off the extra leg from the 

 body'. The leg is fairly well formed, but is a little shorter and a good 



1 The specimen has been mended as nearly as possible in the position originally 

 occupied by the leg. As it may pass hereafter into other hands, it may be well to 



