EEWARDSIA W- ALBUM. 187 



[noted as "third" and "fourth" by error (antea, p. 160)] instars ; 

 the other relates to the spinning done by the larva previous to pupa- 

 tion, and, in spite of the fact that the observations on the latter 

 point were made 177 years ago, it must be confessed that they are far 

 in advance of the more or less superficial notes that we had ourselves 

 collected concerning the silk-spinning habit of this larva (antea, p. 169). 

 Larva (antea, p. 158). — Number of moults: This species appears to 

 have only three larval moults and four instars. I have not reared 

 one specimen through to be able to assert this from my own actual 

 observation, but I have specimens given me as second and third 

 instars, and these fall in between the first and last, with no room 

 for another. Thus the heads of the four instars measured across, 

 from mounted specimens, possibly somewhat distorted, so that the 

 measures are roughly, but not absolutely, accurate, give — 



First instae. 



Second instae. 



Third instae. 



FOTJETH INSTAE. 



0*3mni. 



0"54mm. 



0-99mm. 



l-64inm. 



Taking the first two to be accurate, and the rates of increase of 

 size to be, therefore, as 10 : 18, then the third and fourth instars 

 should be0*97mm. andl*75mm. respectively. These are sufficiently near 

 to the actual measurements, tabulated above, to show that no further 

 instars could be interpolated (Chapman). Second instar (from mounted 

 specimen) (antea, p. 160, line 15) : 5mm. long; head black and shining, 

 diameter of head 0*54mm. The hairs are much more numerous than in 

 the first instar ; the seta? of tubercles i and ii are still distinguishable as the 

 longest dorsal hairs, but are part of a group of 8 or 9 on each side, not 

 definitely marked off from others, about 10 in number, between them 

 and the spiracle. The flange group of hairs is now about 10 in number, 

 and the lower group (of 2 in first stage) vary from 5 or 6 to 9 on 

 different segments. The prothorax has a narrow transverse plate, 

 about 0-5mm. transversely, about 0'12mm. from back to front, it has 

 2 or 3 short hairs on each side ; there are about 16 hairs on each side, 

 above the spiracle, in front of the plate ; on each side of the middle line, 

 close to the front margin of the plate, is a lenticie. On the mesothorax 

 is, on each side, a great dorsal group of about 16 hairs, of which 5 or 

 6 are of the largest size ; this group is continued by 4 or 5 hairs down 

 the posterior margin of segment ; then there is a group of 4 hairs 

 about spiracular level, and a marginal set of 8 or 9, followed by the 

 lower set of small hairs ; no lenticles are clearly observed on this 

 segment, but there is probably a mediodorsal one obscured by some of 

 the hairs. The metathorax is very similar to the mesothorax as regards 

 hairs, but has numerous lenticles — two dorsal, close to middle line, 

 one rather in front of the other, one (on each side) below ii, and a 

 second one on one side, and, on the other side, a lower one about 

 spiracular level. On the 1st abdominal segment the dorsal group of 

 hairs numbers about 12 on each side, of which 3 are large enough to 

 be i or ii ; 7 or 8 between this and spiracle ; 8 or 9 marginal, of 

 which one or two are about as long as i and ii, and the lower set of 

 short hairs ; the lenticles are — one mediodorsal (in middle line), one 

 in front of, but lower than, ii, one above and one behind spiracle, and 

 one between marginal and lower group. The 2nd and 3rd abdominals are 

 much the same. On the 4th abdominal are two mediodorsal lenticles, 



