THE CANADIAN ENTOMOLOGIST. 141 



DESCRIPTION OF FOUR INSECT MONSTROSITIES. 



BY H. F. WICKHAM, IOWA CITY, IOWA. 



The following cases of insect monstrosities have come under my 



notice, and I have thought it best to make them known in order that those 



interested in this work might have access to the descriptions. While but 



little seems to have been written on the subject in this country beyond 



the describing of a number of interesting forms by Jayne (Trans. Am. 



Ent. Soc, VIII.) and Henshaw, Scudder and Hagen (Psyche), it has 



attracted considerable attention in Europe, many writers having published 



accounts, with figures, of more or less interesting cases. With this 



prelude I offer the following descriptions and figures. All the specimens 



are in my own cabinet, deposited in the Museum of the State University 



of Iowa : — 



Fig. a represents the thorax of a specimen 



of PtcrosticJms validus^ Dej., in which the 

 left side is much shorter than the right. 

 There is nothing in its appearance that would 

 indicate this malformation to be the result of 

 an injury to the pupa, so it has been con- 

 sidered worth while to let this case go on 

 record. 



In fig. b is shown a rather curious though 

 not particularly uncommon structure. It is 

 the right anterior leg of a specimen of Trichodes mittalli, taken at Iowa 

 City in July, 18S5. Here the tibia is somewhat stouter than normal, 

 and from near the tip on the outer surface springs a branch, as shown in 

 the cut, having a tarsus which, except for being a little slender, is almost 

 identical with the other. The claws on this supplementary tarsus are, 

 however, not well formed. Aside from this leg the specimen shows no 

 departure from the average individuals of the species. 



A curious monstrosity is seen in a specimen of Polyphylla hammondi^ 

 Lee, which I have tried to reproduce in fig. c. Here the right middle 

 tibia (which is just perceptibly more slender than the normal left one) 

 bears a five-jointed tarsus of the remarkable form shown. The first joint 

 is sub-pyriform in shape, the smaller end articulating with the tibia ; the 

 remaining joints are smaller, and decrease regularly in width, also slightly 

 in length excepting the last ; there are no claws. The large basal joint 

 has on the under surface a transverse impressed line runriing aboiit half 



