HETEROCERA. 



195 



are not certain ; difficulties present themselves in attempting to ascribe certain 

 setae to Pi, and its associates. The whole question may require revision, and 

 the study of a large number of genera, and especially of larvae of the first stage. 

 But the notation here used is consistent with Fracker's * (his Plates III and IV, 

 figures of Hyphantria) : k and -q are united on abdominal segments 1 to 3 ; they 

 are separate on segments 4 to 7 ; rj and n are united on segment 8. (Text-fig. 6). 



6 7 8 9 10 



Text-fig. 6. — Deilemera alba. Abdominal segments 6-10 of full-grown larva. 



Pi is on a brown chitinous plate, on the lateral aspect of the proleg, in all seg- 

 ments in which a proleg occurs, a is a group of small setae, in a subventral 

 position, in all the legless segments. 



On segments 1-8 there is a minute single seta, arising from a well-chitinized 

 base, anterior to the spiracle ; I cannot homologise it with any recognised seta, 

 but it is a very definite and characteristic structure. It is marked x in Text- 

 fig. 6. The coalescence of the verrucae in the two terminal abdominal segments 

 is shown in the same figure. 



The crochets of the prolegs as in all Arctiidae, are uniordinal, heteroideus, 

 and arranged in a mesoseries. 



Conclusion. — The larva of Deilemera alba has a superficial resemblance to 

 that of a Lymantriid ; this is due to the clavate-plumed setae on the mesothorax. 

 That the resemblance is only superficial, is shown by the absence of glands 



* Fracker, S. B. The Classification of Lepidopterous Larvae. Illinois Biol. Monogr. (2) ; 

 July 1915. Forbes, W. T. M. A Structural Study of some Caterpillars. Ann. Ent. Soc. Amer. 

 (3), 94-132. 



