SATURNIA PAVONIA. 321 



have 1 6 along the anterior and inner margin. The head is black, with 

 a number of not very long bristles, 2-jointed antennae, maxillary 

 palpi, a well-developed labium, with a marginal row of minute 

 organs (hairs ?) the largest being distinct palpi at the outer angles. 

 Second instar : Colour black, with a dark buff lunar mark above 

 subspiracular tubercle, almost continuous from segment to segment, 

 but not quite, and, therefore, not a subspiracular line ; since it varies 

 a little from specimen to specimen, it may be a continuous line in 

 some. It is usually present only on the eight spiracle-carrying 

 abdominal segments. When first moulted, the segmental incisions 

 and the bosses of the tubercles are pale. The tubercles are a sub- 

 dorsal (i) carrying a central and 6 surrounding hairs, supraspiracu- 

 lar (iii) similarly armed, but not quite so large ; the hairs are black 

 and strong and of a length equalling about half the diameter 

 of the newly - moulted larva ; tubercle ii of the first instar is 

 now quite lost, nor is the post -subspiracular, called above 

 iv, present, or, if so, distinguishable from the secondary hairs ; 

 the subspiracular tubercle, v, carries 2 or 3 black hairs like those 

 of the dorsal tubercles, but shorter, and 5 or 6 white hairs that 

 are a good deal longer and hang downwards to the surface on 

 which the larva is ; below this are (on 1st and 2nd abdominal 

 segments) 3 ventral (vii, viii, ix) tubercles,, the outer carrying 

 2 or 3 white hairs, the two inner white ones; between these and 

 the subspiracular are several hairs, one or other of which may 

 represent vi. The hairs, at least the central one on each tubercle, are 

 much longer on the 2nd and 3rd thoracic segments. The thoracic 

 tubercles are (on meso- and metathorax) the same as on the other 

 segments, except that vi seems to be present, with several white hairs. 

 On the 1 st thoracic the dorsal and supraspiracular i and iii seem to be 

 fused together. There is often a spot of yellow (continuing the lateral 

 line) at base of v on the pro- and mesothorax ; the 8th abdominal 

 segment as others; the 9th has 4 tubercles and the 10th has 2. There are 

 also a number of hairs on the general surface ; these are short and 

 white, not rising much above the summits of the tubercles, and num- 

 ber ten to a dozen round each tubercle, being scattered freely over 

 the whole surface, i.e., not massed near the tubercle ; several 

 rather larger ones occur below the subspiracular and in front of 

 it and behind it ; there is also a supply in the region of vii and 

 at the bases of prolegs. The normal colouring as already noted 

 is black, with an orange-yellow lateral line, somewhat interrupted, 

 on the first 8 abdominal segments. The only variations noticed 

 are the frequent extension more or less of the orange to the thoracic 

 segments, and, as a rarer phase, the presence of some orange colouring 

 round the bases of the tubercles, the central abdominal segments being 

 first affected, and the lower row (iii) before the upper (i). One specimen for 

 example has alunuleround the front and lower aspect of iii on abdominal 

 segments 2-8, which is a complete circle only on the 3rd and 4th seg- 

 ments ; another has lunules round iii on 3-7 and no complete circles ; in 

 another iii has complete circles from 2-8, and on the thoracic segments 

 and 9th abdominal are also marked yellow lunules, whilst yet another 

 has a yellow lunule below the tubercle on abdominal segments 

 3-8. As this is an anticipation of later colouring it may probably be 

 occasionally more extreme. Third instar : The tubercles as before, fine 



