54 KELLOGG: SCLERITES OF THE HEAD. 



tempes''^ of *Lacordaire. Post-genae seems to me quite the preferable 

 name because of the relation of these sclerites to their counterparts of 

 the front of the head (the genae). In archippiis the post-genae are 

 large, and are only indistinctly set off from the epicranium and genae, 

 as explained under "Genae," and "Epicranium," antea. In most 

 lepidoptera, however, these limiting sutures are distinct (see su" in 

 figs. I and 3, Plate II; see also references to species and drawings 

 under "Genae," and "Epicranium," aniea). The post-genae extend 

 in on each side to the occipital foramen, and often (perhaps always 

 in carefully handled specimens) appear to be connected by a sub- 

 transparent transverse bar running across the foramen. This bar is a 

 portion of the tentorium of Burmeister, or "internal skeleton" of the 

 head (see tent in fig. 9, Plate II). The post-genae extend upward 

 and forward till they meet the genae; and they extend downward and 

 forward till they meet the other ends of the genae. This meeting 

 place is usually, among lepidoptera, about opposite the insertions of 

 the labial palpi, and the suture between genae ami post-genae can 

 usually be distinguished with difficulty. This suture is plain in Proio- 

 parce Carolina and indistinct in archippus. 



Gula. 



The gula is distinguishable in archippus, if at all, with difficulty. 

 That part of the external cranial skeleton bounding the occipital 

 foramen below should belong to the gula; but where I have examined 

 this region in archippus, the lower boundary of the foramen api)eared 

 to consist of a portion of the tentorium or internal skeleton of the 

 head i^sce gu in fig. 9, Plate II); and this portion seemed intimately 

 united with the basal part of the labium. In other lepidopterous 

 forms a gula, intimately united with the labium, appears to be present. 

 An ele\ated line or ridge often seems to indicate the probable posi- 

 tion of the obsolete suture between the two sclerites, as in Triptogoft 

 modesia (see gu in fig. 7, Plate II), and in Catocala sp. (see gu in 

 fig. 13, Plate II). 



THE MOVABLE PARTS. 



Antennae. 



I have nothing to add to the familiar characters of the antennae. 



Labrum. 



The labrum presents an interesting condition in archippus, as, 

 indeed, it does in the lepidoptera generally. It is a narrow, trans- 



♦Lacordaire. Th.. Introduction a 1" Entomologie. p. 2.57. 1834. Paris. This reference to 

 '• les tempes (tempora)" seems to be translated almost literally from Kirby and Spence's 

 Introduction (see foot-note reference;. 



