24 ENTOMOLOGICAL SOCIETY 



ulate insects, though quite different in the different groups. In the 

 Gallerucini the galea and lacinia are distinct, and both well de 

 veloped, but in all others the lacinia is rudimentary, usually being 

 represented by a small prominence bearing a large spine at the 

 inner base of the galea. The setae upon the palpi and stipes are 

 very constant in position, as they are on the mentum and sub- 

 mentum. The labial palpi are small and of one or two segments, 

 the palpiger being distinct only in the Cryptocephalidae. 



I have not, as yet, succeeded in satisfactorily homologizing the 

 sclerites of the ventral part of the head. To the caudal margin 

 of the submentum and the caudal margin of the occiput is at 

 tached a membrane which is continuous with the prosternum. / e. , 

 there is no suture between them. Beneath this membrane just 

 caudad of the caudal margin of the submentum, attached at either 

 side to the ventral margin of the epicranium and with the cardos 

 of the maxillae articulating upon its anterior margin at either side, 

 is a rectangular, well chitinized sclerite, which seems to be 

 similar to the gula of the adult beetles and yet also seems to bear 

 exactly the same relation to the other sclerites as does the tento- 

 rjiuiLof the Orthoptera. That it is the same I am not prepared 

 to say. Lying beneath the membrane to which the mentum is 

 attached and connecting the epicranium, it seems to form the 

 floor of the epicranial segment. 



Before proceeding to describe the thorax and abdomen it may 

 be well to explain the system of notation which I have used for 

 describing the body tubercles and setae. But first I wish to re 

 quest that no one will ask me later on " What is a tubercle or 

 seta," for I freely confess I don't know, though I have tried hard 

 enough to find out. Tubercles, spines, setae, and hairs or acces 

 sory setae, shade into each other so gradually and their structure 

 is so variable that I am at a loss to know, how to define them and 

 have not by any means secured a satisfactory knowledge of their 

 morphology. That the tubercles and setae of larvae are of great 

 taxonomic value has already been well shown in the case of Lep- 

 idopterous larvae by Dr. Dyar and others. They have also 

 been used considerably in the classification of Saw-fly larvae. In 

 the present study I have found them of the greatest value and in 

 terest. There seem to be a more or less definite number of setae 

 in the most generalized larvae which are variously modified in 

 number and position in those more specialized. When these 

 setae are surrounded by a thickened or pigmented area, or where 

 they surmount a protuberance of the skin, I have called them 

 tubercles. Often, however, the surface of the epidermis is uni 

 form in texture, merely being divided into areas by folds. In 

 such cases the usual setae are sometimes distinct and easily recog 

 nized, but many times they are surrounded by a large number of 

 small accessory setae from which they are not distinguishable, as 



