﻿OP THE STATE ENTOMOLOGIST. 177 



superiorly with close-shorn bristles as in yucccc, such bristles generally springing from 

 minute papilh«. The newly hatched larvai of the two divisions approach each other 

 more nearly in general appearance, as all animals do, the farther we go back to the 

 commencement of individual lite; but though the newly hatched larva of Vuccce bears 

 a general resemblance to the same stage in many endophy tons Heteroberous larvae {e.g. 

 Xyleutes, Cossiis,) yet in the stiff hairs springing from the general surface, or from very 

 minute points, instead of from distinct tubercles, it agrees with the Rhopalocera. The 

 legs, both false and true, together with their armature and the trophi, are so extremely 

 variable in both divisions that comparisons can hardly be instituted. The endophytous 

 habit, though very exceptional, is found in butterflies (e.g. Thecla Isocrates, Fabr. : see 

 Westwood's Intr., ii., p. 369.) None of the Heterocerous borers, so far as my expe- 

 rience goes, line their burrows continuously with a matting of silk; but use the silk 

 very sparinjjly, or not at all, till about ready to pupate. The larva of Yuccce, for the 

 most part, lives in a tube of silk, which it builds and extends often several inches be- 

 yond the trunk or stem in which it burrows, and from which it often, especially when 

 young, issues to feed. In this, again, it approaches the Hesperians, which are partial 

 concealers, and live, when not feeding, within silken cases or tubes constructed among 

 the leaves of their food-plants. 



The pupa; of the Castnians, like those of all Heterocerous borers known to me, are, 

 according to authors, armed with lings of minute spines on the hind borders of the 

 abdominal joints — the spines serving a very useful purpose in assisting the pupa out of 

 its cocoon. Heterocerous borers also pupate in a more or less perfect cocoon, made 

 either within or without the burrow ; and, in the issuing of the imago, the mesothora- 

 cic covering generally collapses, the leg-cases become unsoldered, and those of the an- 

 tennae are always separated and often curled back over the head in the exuvium. The 

 Hesperians pupate within the silken cavity occupied as larva, or else in a separate 

 slight cocoon : the pupa is generally attached to a silken tuft by the hooks of the cre- 

 master, and sometimes by a silken girth around the middle of the body besides ; it is 

 not unfrequently covered with a slight powdery bloom, and is characterized by the 

 prominence of the prothoracic spiracle ^ : the exuvium more nearly retains its form, 

 the leg-cases remaining soldered, and even those of the antennie being rarely separated. 

 In not having a well-formed cocoon, in being covered with bloom, in the characters of 

 the exuvium, in the conspicuity of the prothoracic spiracle, but more particulai-ly in 

 the want of minute spines on the borders of the abdominal joints, Yucca: is again Hes- 

 perian and not Castnian. Indeed, except in the broader anal flap, densely surrounded 

 with stiff" bristles, in place of an apical bunch of hooks, in the smaller head and larger 

 body, it resembles Nisoniades in general form, color, and texture. 



The typical Castnians, in the perfect state, have the wings large with loose and 

 very large scales, and the hind-wings invariably armed, at costal base, with the lo?ig 

 stout sjrine, or spring, which serves to lock the wings in flight by hooking in a sort of 

 socket beneath the primaries, and which is so characteristic of ihe Heterocera. The 

 venation resembles more nearly that of the Hepialians, and is totally unlike that of the 

 Hesperians. The veins are slender ; in the primaries la and 5 are as stout as the rest ; the 

 discal cell is short, connected transversely with 3 and with an areolet above : in the 

 secondaries the cell is nearly obsolete, and the independent or vein 5 of secondaries is 

 as stout as the others. (Comp. Fig. 54 a. b. with Fig. 55 ) The antenna, though thick- 



* lu Nisoniadcs Juvenalis (FabrJ tliis spiracle takes the Ibiin ol a prominent sooty-black horn or 

 tubercle . 



E R— 31. 



