PACKARD. — TRANSFORMATIONS OF SATURNIAN MOTHS. 561 



The head is smooth, pale-green, black behind the eyes, the black ex- 

 tending up towards the back of the vertex ; it is nearly as wide as the 

 1st thoracic segment, which is considerably narrower than the two follow- 

 ing. The tubercles are now more prominent and are green and pale 

 turquoise-blue. The four dorsal ones on the 1st thoracic segment are well 

 developed and higher than before, the two middle ones nearly a quarter 

 larger than the outer ones, each bearing six stiff straight black setae. 

 The spiracular one is pale turquoise-blue, as all the others of this series 

 to the end of the body. The two dorsal tubercles on the 2d and 3d tho- 

 racic segments considerably (about one-sixth) larger than those on the 

 abdominal segments and those on the 3d thoracic considerably larger than 

 those on the 2d segment ; they each bear eight black stiff setae, seven on 

 the crown with an eighth in the centre ; these are yellowish at base, beyond 

 turquoise-blue ; in the examples I bred the tubercles on the 2d thoracic 

 segment were green. The setae on the thoracic tubercles are not more 

 than a quarter larger than the tubercle itself. All the dorsal abdominal 

 tubercles are green (or yellowish green, Joutelj, bearing each four black 

 stiff and straight setae, one of them being usually small ; the longest setae 

 are about one-third longer than the tubercle itself. The dorso-median 

 tubercle on the 8th abdominal segment, unlike all the other abdominal 

 ones, is turquoise-blue ; it is fully twice as thick as those on the 7th seg- 

 ment. It does not show its double origin as there is a central seta, and 

 one behind it on the median line, with tliree on each side of the two ; 

 they are not arranged on each side of the median line. 



On the side low down are two or three minute black dots below each 

 of the turquoise-blue tubercles of the lowest series. 



Suranal plate and its tubercles pale straw-jellow, concolorous with 

 the rest of the body, with a large black roundish spot in the centre. In 

 those reared by Mr. Joutel, the two tubercles on this plate are turquoise- 

 blue. Spiracles black, fairly conspicuous. Anal legs green, centred 

 on the outside by a rather large and conspicuous black spot ; the mid- 

 abdominal legs are green or yellowish green ; thoracic legs black. 



On June 2d the larva had become 18 mm. in length, otherwise it did 

 not differ from its appearance directly after hatching. 



Mr. Joutel's figures illustrate the wide colorational differences exhib- 

 ited in the same brood of caterpillars. Some represent an entirely yellow 

 individual, except the eleven turquoise dorsal tubercles, and those of the 

 infraspiracular row ; and the black lateral line, which is wanting in some 

 of his specimens and mine. lie found all variations between these and 

 the very dark larva. In the 2d stage of the larva the body and tubercles 



VOL. XXXIX. uQ 



