44 



THE BRITISH NATURALIST. 



[March 



find: — "Allied to the preceding (acantiiodactyliis), but the ground 

 colour of the fore wings olivaceous." 



Variation — This species does not seem to vary. All writers 

 appear to agree in considering it a most constant species. In the 

 "Entomologists' Monthly Magazine," Vol. XVIII., p. 117, cosniod- 

 actylus is described as very common and very variable in America ; 

 but it is questionable whether this is identical with our British 

 pn:ictida:tyla. 



Larva — The larva is thus described by Mr. Porritt : — " Length 

 about half-an-inch, and of the usual stumpy form when at rest. Head 

 small, and narrower than the second segment ; it has the lobes 

 rounded, and is highly polished ; body cylindrical, attenuated a little 

 posteriorly, each segment plump and distinct, making the divisions 

 clearly defined ; skin soft, and sparingly clothed with short hairs. In 

 colour there are two very distinct varieties. In var. i (which, judging 

 from the larvae sent me, is the rather commoner form) the ground 

 colour is a clear purplish-pink ; head very dark sienna-brown, almost 

 black ; the smoke-coloured dorsal vessel shows through as the dorsal 

 stripe ; sub-dorsal stripes clear white, and very conspicuous ; below 

 them is a narrow and interrupted white line, and another about the 

 same width - but being tipped with pink is not so pale— along the 

 spiracles ; hairs white. Ventral surface semi-translucent, yellowish- 

 grey ; pro-legs purplish-pink on the outside ; anterior legs of the dark 

 sienna-brown colour of the head, but with paler rings. In var. 2 the 

 ground colour is bright pale green, the markings same as in var. i, 

 except that the white stripes are scarcely so conspicuous ; in some 

 specimens the smoky medio-dorsal vessel is tinged with pink ; the 

 ventral surface and the pro-legs are of the same bright green as the 

 dorsal area. Some of the larvae were intermediate between these 

 varieties (" Entomologist's Montlily Magazine," Vol. XXII., p. 150). 

 Tliesc descriptions were made from larvae obtained by Mr. Eustace 

 Bankes of Corfe Castle, on Stachys sylvatica, in 1884 and 1885. 



Comparing the larvae ol puiictidactyla with that of acanthodactyln, 

 ]Mr. Porritt writes: — "It will be noted that the chief points of dis- 

 tinction (distinctions which will probably be found reliable) are the 

 dec]) purple ground cohjur in acaidliodactylus as compared with the 

 jjurplish-pink of puiictidactyiiis ; the white sub-dorsal lines being less 



