478 BRITISH LEPIDOPTERA. 



hairs, the 2nd instar of the larva of H. tityus represents possibly 

 a more primitive condition than the 1st of an Amorphid larva, 

 whilst the 3rd instar of H. tityus is but little in advance of the 

 1st of Smerifithus (ocellata), and certainly not so advanced as the 

 2nd of Amorpha (populi) where the hairs are already waning in 

 favour of the mammillary bases..] Traces of the oblique stripes 

 (anus to head slope) above the subdorsal line are already observable 

 on the middle abdominal segments. Fourth instar (July 27th) : 

 The larva is now i'i25in.-i'25in. in length, including the caudal 

 horn, which slants slightly upwards, but has a downward curve 

 at its point, making it appear somewhat horizontal. The shape 

 is much as in last instar, but the larva is a little plumper, not tapering 

 so much towards the head, nor showing so marked a tendency to 

 narrow at the rst and 2nd abdominal segments, although it still 

 tapers somewhat to the caudal horn. The subsegmental divisions are 

 fairly clear ; and there is still a slight tendency for the first 3 

 subsegments to unite into a single subdivision to be observed if 

 carefully looked for. The colours and markings as before but the 

 crimson slashes, both above and below the subdorsal line, are 

 stronger ; below the subdorsal, across the spiracles on abdominal 

 segments 2 to 7, they are definite stripes (with head to anus 

 slope) faintly bordered by pale yellow or yellow-green, whilst, on 

 the 1st and 8th abdominals, they are still mere spots ; above the 

 subdorsal they form very short streaks (with a tendency to slope in the 

 reverse direction) on the 2nd to 7th abdominals, and small spots on the 

 1st and 8th ; the greater part or whole of these upper streaks is on the 

 first three subsegments.* The caudal horn is dark purple. The venter is 

 purplish-black, this tint shading off into the green lateral area and 

 showing pinkish at the junction, the prolegs being shaded with this 

 colour. The head, pro- and mesothorax are more of an apple- 

 green tint in contrast with the yellower green of the remainder 

 of the body. The legs are pinkish. The spiracles brown centrally, 

 white at either end, surrounded by a black chitinous rim. The 

 mammillary hair-bases are still opalescent white, and the hairs very 

 much longer than is usual in Sphingid larvae at this stage ; they are 

 still slightly forked at tip and this gives the larva a very soft furry 

 appearance, resembling that of an Amorphid larva in its first instar, 

 when seen under a lens. The hairs on the head and scutellum are 

 black, and not noticeably, if at all, forked ; those on the body are, for 

 the most part, pale and clearly forked and more numerous than in 

 any other Sphingid larva known to me, at this stage, there being 

 more than one row on a subsegment ; the mammillary bases are 

 of course not so large as those of the Amorphid larvae but are still 

 quite prominent when viewed with a lens. Fifth instar (August 5th, 

 adult): i*5ins. long at rest, i'75ins. when crawling, -j^-in. in girth, 

 and fin. in height, the body slightly raised when at rest. In shape 

 the larva is short, stout, and plump, cylindrical and tapering 

 gradually towards head and anus, more gradually towards anus and 

 slightly more rapidly towards head, which is rather larger than is 



* One of the special points about the larva of H. tityus is the fact that it 

 combines both the forward sloping and backward sloping series of oblique stripes in 

 its scheme of coloration, and although the upper scries is less distinct and more 

 confused than the lower, the tendency is clear enough (Bacot). 



