310 BRITISH LEPIDOPTERA. 



(two on each) is to produce the appearance of a very indistinct line 

 above and parallel with the anterior part of the subdorsal ; this 

 line is also contributed to by the smaller dots.* As the small 

 anterior oblique stripe does not reach the subdorsal, but stops at 

 about the level of the hinder end of this indistinct line, there is an 

 appearance of continuity between the anterior stripe and the line ; this, 

 however, does not really take place, as the former stripe is prolonged 

 for a very slight distance below the posterior end of the horizontal line. 

 These markings are very persistent in after stages, and are, therefore, 

 described in detail. f The ist stadium lasts about 6 or 7 days; 

 at its close (before moulting) the larvae are about 12mm. long when 

 extended in walking i pi. vii., fig. 2); the larva is about io^mm. long 

 when rather retracted at rest, the horn 4mm. long (Poulton). Second 

 instar: The larva is now covered with mammillated tubercles, 

 precisely as in the Amorphid larvae, each tubercle carrying a minute 

 hair, some apparently only thickened a little at the end (seen 

 edgewise?) others definitely bifid. The head in ist stage carrying 

 simple hairs on a smooth surface is now mammillated also, but has 

 a rounded vertex (not produced into a horn as in Smerinthiis). The 

 true legs are slightly affected by the mammillation. The horn is 

 relatively shorter than in stage 1, and the mammillae fewer than 

 the hairs in stage 1 (Chapman). The primary setae still show 

 conspicuously because of their larger size, but, in this skin, the 

 secondary hairs, borne on mammillae, are a well-marked and 

 conspicuous feature ; these secondary hairs appear to be short and 

 stiff and slightly bifid at tip, whilst the bases are tall and conical 

 (Bacot). The markings of this stage almost exactly resemble those 

 of the last % (see, loc. cit., pi. vii., fig. 3), and the origin of the lines 

 and stripes from linear series of shagreen-dots is equally § obvious. 

 The large spots and long hairs have now disappeared % except 



* Not till the second instar unless by showing through the skin. 



f This statement probably explains Poulton's faulty description of the larva 

 in its 1st instar. He describes these markings in detail in stage 1, because "they 

 are very persistent in the after stages." How could he have known when the larvae 

 were in stage 1 that the markings were going to be " very persistent in the later stages ? " 

 The fact is that almost the whole of the structure and markings, as here described, are 

 those of stage 2, which Poulton has apparently carried back as a guess to stage I. This is 

 clearly evidenced by his statement (Trans. Ent. Soc. Land., 1885, p. 283) prefacing the 

 description here given, in which he says, after referring to the primary seta?, which he calls 

 the "long" hairs, "In addition to these long hairs, there must be a comparatively 

 thick coating of much smaller ones. I was able to prove their existence at a later 

 date by the use of the compound microscope, or even by a powerful hand lens, but 

 I was away from home and without a sufficiency of appliances when the larvae were in 

 the ist stage. There can be no doubt of their presence, and they cover the horn as 

 well as the body." Not having seen them in stage 1, but being convinced they were 

 there, and having become convinced later of their importance, he has evidently carried 

 back his observations on these particular structures made in the later stages to stage 

 1, and dealt with them as if he had actually observed them in this stage, which is 

 altogether misleading and unscientific, and the facts as applied to stage 1 unfortunately 

 happen to be entirely erroneous. 



J This must be read in connection with our last footnote, explaining that 

 Poulton's markings of stage 2 were evidently written back into stage 1. 



§ The formation of these is obvious in this (2nd) instar, there are no shagreen- 

 dots in the 1st instar, so the origin of the lines from them then is not to be made out. 



II We have no knowledge of Poulton's " large spots "which he has described as 

 being at the base of the " long hairs," />., primary seta.% unless they refer to the 

 chitinised skin surrounding the bases of the primary seta; ; but he is wrong in saying 

 that the latter have disappeared in this instar, for they still show conspicuously, although 

 less easily detected, now that they are surrounded by secondary shagreen-hairs. 



