THE CANADIAN ENTOMOLOGIST. 137 



upon the pith inside the thorns of G. triacanthos ; the one first described 

 below I am satisfied is the larva of this species ; what the other is I do 

 not attempt to guess, but I append a description of it because of its 

 singular structure. 



That which I believe to be the larva of Gleditschiceella is about three 

 lines long, rather fat and sluggish, yellowish white, with the head and a 

 line which is interrupted in the middle, across the first segment after the 

 head, just behind its anterior margin, ferruginous. Feet, sixteen. The 

 pupa is not enclosed in a cocoon. I have found a few larvae and several 

 fresh pupae in the latter part of April. 



The other larva is white, about four lines long, cylindrical, with the 

 segments distinct and clothed with scattered white hairs. The thoracic 

 legs are very distinctly divided into segments, have no terminal claw, each 

 segment being surrounded near its apex with a circle of rather stiff ciliae ; 

 the anal feet are small and indistinct, and there are no ventral prolegs ; but 

 there arc six pairs of dorsal prolegs or large tubercles which represent 

 them ; these " dorsal prolegs,'"' if I may so call them, are as large and 

 distinct as the true legs ; they have no terminal claw, nor any coronet of 

 tentacles, as in ordinary ventral prolegs, but each one is bifid at its tip, or 

 to speak perhaps as correctly, each one ends, in two small tubercles, and 

 progression is mainly effected by these false legs. In crawling the thoracic 

 and anal feet rest upon one surface, while the dorsal or false feet rest upon 

 the opposite one, the body being curved so as to accomplish this 

 purpose. 



The larvae of Gleditschiceella were found in living thorns, or those 

 which had not been long dead ; and a single larva evidently eats but little 

 of the pith. The larvae with the dorsal legs were found at the same time 

 in dead thorns, which had previously been burrowed by the larvae of 

 Gleditschiceella, and in which was the small hole through which the imago 

 of that species had emerged the previous year. No other means of 

 ingress or egress was observed besides this hole, and this singular larva 

 could not now pass through this hole. It was feeding on the dead 

 pith. Small white silken cocoons, between three and four lines long, were 

 found in some thorns ; most of them were a year or more old, and were 

 empty, but one of them contained a pupa which unfortunately was 

 destroyed in opening the thorn. Several dead larvae were also found, but 

 they were so completely encased in multitudes of little Chalcid pupae that 

 it was impossible to determine the larvae. A little Chalcid larva was just 

 emerging from one of the larvae of Gleditschiceella. 



