THE CANADIAN ENTOMOLOGIST. 207 



MERISTIC VARIATION IN CORYDALIS CORNUTA, LINN. 



BY H. F. WICKHAM, IO>yA CITY, IOWA. 



Records of duplication of members in hexapod larvae are so rare that 

 I submit the subjoined account, drawn up from a specimen of the young 

 of Corydalis cornuta, captured in the river near Iowa City, several years 

 ago. The insect is one of a number that I took for class dissection, and 

 as far as noted, the remainder did not depart from the ordinary type. A 

 notice of the case was prepared at the time and sent to a scientific journal 

 on the eve of its suspending publication, so that I think the article was 

 never printed. 



The larva under discussion measures, in its preserved state, about an 



inch and three-quarters in length. The duplication of parts concerns the 



left hind leg, where the femur, which is normal, bears a bifurcate tibia, one 



branch of which is longer than the other. The longer side attains a length 



about equal to that of the right tibia, and bears a tarsus which is 



approximately normal, though the claws are nearer together than usual ; 



/««-». the shorter side of the tibia supports a tarsus, 



I A which in its turn shows a decided tendency to 



J \ bifurcation and carries two pairs of claws. 



d v^C-, \ The proportions of the parts are shown in the 



/ I \ \ figure. (Fig. 8.) I am not certain that the 



^t^ \\ short tarsus is drawn in proper perspective, 



\ \ as I accidentally broke it off at the joint 



\ \ marked a in the figure, and may have twisted 



]? it in replacing. The specimen is preserved in 



my collection. 



PREOCCUPIED NAME. 

 I refer to Prof. Fernald's kind notice of my " Hawk Moths," Can. 

 Ent., 98, 1887, for the statement that the generic term ^/;-<fz/.f is pre- 

 occupied, having been used by Koch in 1837 for a genus of Scorpions. I 

 should not have troubled myself further in the matter of changing this 

 name in the Sphingidae, seeing that Prof. Fernald believes a separate 

 genus iox plebeia from Protoparce unnecessary, except that Rothschild and 

 Gordon, in their exhaustive revision of the Sphingidse, just published, 

 retain the name Atreus and criticise my calling the species '' plebeius,'' 

 instead of plebeja. So I change the name Atreus, Grote, 1S86, to 

 Paratrea, with P. plebeja as type. A. R. Grote. 



July, 1903. 



