PHRYXUS LIVORNICA. 155 



legs yellow-grey. Head dark rose-red. Of the latter colour is also 

 the rather strongly-expressed dorsal line. The caudal horn is black 

 beneath, and only red above. Spiracles whitish or yellowish, black- 

 margined. (2) An aberration, sometimes occurring locally, has a 

 broad black dorsal line, which extends laterally on each segment 

 as far as a round, white or yellow, black-margined spot. This 

 touches a light double lateral line, whose lower part is rose-red 

 spotted on each segment. The belly, legs and head are black, the 

 horn red beneath, black above. Allard observes (Ann. Soc. Ent. Fr., 

 1867, p. 315) that the larvae found at Biskra (feeding on Euphor- 

 biaceous plants) differ somewhat from those seen in mid-France, 

 being larger and brighter, and Oberthur also notes (in litt.) that 

 the larvae at Biskra offer a very pretty melanic form, of which he has 

 several examples in his collection. Boisduval speaks of the larva as 

 " cette belle chenille, qui varie beaucoup,' , and suggests that, in all its 

 variations, the distinctive mark is the subdorsal pale line, generally 

 bearing on it the row of pale spots. He figures (i) A larva, with deep 

 red head, prothorax, dorsal line, caudal horn and anal prolegs, and says 

 that the ground-colour is " noiratre ou d'un brun roussatre," the 

 transverse bands black, the subdorsal line and row of spots pale 

 yellow, the sides irrorated with yellow dots, the venter pinkish, 

 the horn slightly curved. (2) A larva of pale green* hue, with 

 lilac dorsal stripe, a subdorsal row of whitish spots suffused with 

 pink, placed on a whitish line, the sides irrorated with white spots, 

 a pinkish subspiracular line, and a brown straight horn. 



Development of larval markings. — The larva of this species 

 possesses almost the same markings as that of Cekrio gallii in its 4th 

 stage, i.e., a subdorsal line with interpolated ring-spots ; all examples 

 examined agree in having the ring-spots sharply distinct from the 

 whitish subdorsal line, so that the latter is thereby interrupted. 

 Figures of the adult larva are given in the works of Hiibner, 

 Boisduval and Duponchel. In most specimens the ground colour 

 is brown, although Boisduval also figures a light green specimen, from 

 which it may be inferred, from analogy with C. gallii and Thanmas 

 vesftertilio, that the first stages are green. A young larva (in coll. 

 Staudinger), probably in 4th stage, has the ground colour light 

 ashy-grey ; the dorsal and subdorsal lines are white, the latter 

 showing, in the positions where the ring-spots subsequently appear, 

 small white " mirrors " with red nuclei, exactly corresponding to the 

 stage of T. vespertilio, represented in pi. vi., fig. 49^. The i( mirrors " 

 are nothing more than dilations of the subdorsal line, which is 

 not, therefore, interrupted by them. The black " ground area " 

 does not surround the " mirrors " completely, but borders them 

 only above and below, and is much more strongly developed above, 

 extending in this direction to the dorsal line. . . . The adult 

 larva of the American P. lineata, Fab., differs from that of P. livornica 

 in remaining permanently at the 4th stage of the last-named species. 

 The ground colour of the larva is green, the subdorsal band yellow, 

 bordered with black, slightly curved, arched lines, which nowhere 

 interrupt its continuity, so that the North American species appears 



* Hellins believes this to have been figured from a blown larva, and considers 

 that this would account for the pale colour and the shape of the horn. 



