238 



ENTOMOLOGICAL NEWS. 



[Sept., '04 



ture, which should be placed on record, the literature of this 

 subject being none too voluminous. 



The abnormality manifests itself in the right hind leg ; the 

 coxa and trochanter are normal but the femur is more flat- 

 tened beneath than its mate. The tibia is a trifle longer than 

 it should be, the outer edge almost straight, the inner edge 

 curved, tip dilated, the upper apical margin produced into a 

 sharp point. From this dilated apex, which of cour.se repre- 

 sents the consolidation of a pair of tibiae, springs, first, a tar- 

 sus which is nearly normal except that it is slightly undersized, 

 and, second, a paired organ (external to the first), which 

 is composed of two tarsi uriilcu at base. The basal joint 

 of this paired organ is broader than 

 that of a normal tarsus, the second 

 joint is twice as broad. at apex as at 

 base and is furnished at tip, in the 

 middle line, with a bunch of small 

 spines. From each side of this broad 

 apex arises a well-formed ramus of 

 three joints, the terminal ones bearing 

 each a pair of normal claws. 



Instead of the usual number of tibial 

 spurs (two) we find that this leg bears 

 three. The two internal ones, which 

 may be assumed to represent the nor- 

 mal pair, do not differ essentially from those of the other leg, 

 but the third, which is located on the middle of the inferior 

 apical margin, is trifurcate at tip. 



The accompanying figure is rather diagrammatic, but will 

 show the general arrangement of the parts described. It will 

 be noticed that the opposed surfaces are correlative or nearly 

 so. They appear to occupy the position DAA of Bateson's 

 scheme, illustrated on page 481 of his work, "Materials for 

 the Study of Variation." The composite structure of the 

 second joint of the supernumerary tarsus is well shown by the 

 disposition of the hairs on the upper surface and of the small 

 spines on the lower. Only the former appear in the figure, 

 which shows a view from above. 



