500 MERISTIC VARIATION. [part I. 



765. Scarites pyracmon (Carab.). At base of posterior face of the 

 trochanter of left normal front leg, immediately above the cotyloid 

 articulation was implanted an elongated lanciform joint. This joint 

 was directed backwards and represented a pair of trochanters com- 

 pounded by their anterior surfaces. With each of the two apices of 

 this double trochanter was articulated a complete leg, in all respects 

 formed as an anterior leg. The two moved as a complementary pair. 

 [Details given. This is one of the earliest and best described cases. 

 AsMUSS 1 in quoting it points out that the description and figure plainly 

 shew that the two extra legs were a pair, a right and a left, respect- 

 ively. They were in fact a pair, arising from the posterior surfaces of 

 the normal leg, and presenting their anterior surfaces to each other.] 

 Lefebvkk, A., Gu&rin's Mag. de ZooJ., 1831, Tab. 40. 



766. Geotrupes mutator (Lainellicorn) : two supernumerary limbs arising from 

 femur of right anterior leg. Femur greatly widened, upon posterior border giving 

 off a large prominence which divides into two processes at right angles to each 

 other. Each of these processes bears a normal tibia and tarsus, but the foremost of 

 these tibiae is shaped as a left tibia, having its serrated border placed anteriorly, 

 while the other extra tibia is formed as a right tibia, having its serrated border 

 placed 'posteriorly. [The pair of limbs arise from the posterior surface of the normal 

 limb and have their anterior surfaces adjaceut, as in Position P.] FRiVALDsm:, J., 

 Term. Fuzetek., 1886, x. p. 79, PI. 



76/. Pterostichus lucublandus ? (Carabidre): third tarsal joint of left middle leg 

 at apex presents wide articular surface. On this stands a triple 4th joint, made up 

 of a single anterior portion, bearing the rest of the normal tarsus and a posterior 

 portion, double in structure, the two parts being completely united. The single 

 anterior part of this 4th joint bears a normal 5th joint with claws. The double 

 posterior part of the 4th joint bears a pair of separate 5th joints, each having a pair 

 of claws. Of these the anterior is perfect, but the peripheral part of the posterior 

 5th joint is crumpled, so that its claws are twisted out of position, but at its base it 

 stands exactly as the normal 5th joint, and as the 5th joint of the anterior extra 

 tarsus, all three being in the same horizontal plane. These extra parts, therefore, 

 are in the Position marked P in the Scheme and have the relations there indicated 

 for that position. This specimen was kindly lent to me by Mr Harrington, who 

 first described it Can. Ent., 1890, xxn. p. 124. 



(8) Positions VPP to VVP. 



*768. Ceroglossus valdiviae, Chili (Carabidse): left anterior tibia 

 bearing a pair of supernumerary legs. The tibia widens, and in 

 its middle part gives off posteriorly and ventrally a wide branch 

 having the form of a pair of tibial apices compounded together. 

 The double tibia bears two tarsi (Fig. 166, B! , L') having a common 

 proximal joint, but these have unfortunately been broken, two 

 joints being missing from the one and three from the other. The 

 legs are a right and left as usual, and they stand in the relative 

 positions marked VPP in the Scheme. This is a very simple 

 and striking case, for the animal is of good size and the parts 

 are well formed. The two tibial spurs which are adjacent in 

 the two extra tibiae are compounded so as to form a double spur 

 with two points as shewn in the figure. As shewn for the Position 



1 Monstrositates Goleopterorum, 1835, p. 44, PI. 



