chap, xx.] EXTRA LEGS : UNCONFORMABLE CASES. 



509 



slender and the whole thickness of their common proximal joint is 

 even less than that of the proximal joint of the normal tarsus. The 



Fig. 171. Clytus liciatus, No. 782. I. View of right tibia. II. Detail of the 

 extra parts, from plantar surface, ac, ac, claws supposed to be morphologically 

 anterior, pc, rudiments supposed to represent posterior claws. III. Enlarged 

 view of the end of the normal tarsus. (The property of Dr Kraatz.) 



terminal joints of the extra tarsi are well formed, but they each bear 

 only one fully developed claw, the claw of the adjacent side of each 

 being only represented by a rudimentary knob. It appears at first 

 sight that these extra tarsi are at their origin from the tibia only a 

 single appendage and that their double nature only begins from the 

 third joint. This however is not the case, for there are five spurs on 

 the tibia, together with a small brown knob which perhaps represents 

 the sixth spur. The tibia is greatly misshapen and the arrangement of 

 the spurs is so amorphous that I did not succeed in determining their 

 morphological relations. This specimen was kindly lent by Dr Kraatz, 

 having being first described by him in Berl. ent. Zt., 1873, xvn. p. 433, 

 figs. 1 7 and 17 a. 



Cryptobypnus riparius (Elater. ). The tibia of the right anterior leg is 

 enlarged at its apex and bears one very large tarsal joint : this joint has two apical 

 articulations, of which the posterior bears the remaining 4 joints of what is pre- 

 sumably the normal tarsus. The other articulation bears a large tarsal joint, common 

 to a pair of complete extra tarsi. This pair of tarsi stand with their lateral parts 

 closely adjacent and their plantar surfaces downwards, but the other tarsus which 

 is posterior to them, and is presumably the normal, stands with its plantar surface 

 turned backwards. This disposition differs considerably from that indicated in the 

 Scheme. For the place of origin of the extra tarsi and their position relatively to 

 each other is A; but the normal tarsus is twisted so that it turns its dorsal surface 

 forwards, towards the posterior surface of the nearer extra tarsus. For this specimen 

 I am obliged to Dr Mason. 



Taurtiina nireus (Lamell.) : right middle tibia bearing two extra tarsi. [In 

 the normal leg of this beetle the tibia is like that of many other Lamellicorns, 

 presenting at its apex two sharp processes, the one anterior and the other dorsal : 

 and ventrally two articulated spines, one anterior and the other posterior to the 

 tarsus. The abnormal tibia of this specimen is considerably widened at its ajjex, 

 and bears in addition to the normal two processes two other processes of a similar 

 kind separated from each other by a pair of articulated spines. Instead of a single 



