132 Journal New York Entomological Society. [Voi. v. 



effect on the generic location of the species ; it is probably the result 

 of comparatively recent adaptation. 



Hyphantria cunea. 



Tubercles small, normal, two small areas detached from the cervical 

 shield probably represent the two outer primitive setje. Setge all single 

 as in S. virginica, but on the thorax subprimary seta iii is situated on a 

 small wart behind seta iv and on the abdomen subprimary vi is present 

 on segments i to 8, small anteriorly, but of fair size further back. 



In this larva there is no precocious wart formation, but the subpri- 

 mary setae appear in stage I almost perfectly formed (v is absent on 

 thorax). According to my views, the Arctiida are descended from the 

 Noctuidce, and here is a case where the specialization of the larva has 

 crowded back into stage I the typical structures of the Noctuidce, the 

 primitive first stage being absent, yet without the supervention of wart 

 formation until stage II. 



Halisidota maculata. 



As in S. virginica, but for a doubling of setse iii on abdominal seg- 

 ments 1 to 8 and the partial fusion of iv with iii. Subprimary tuber- 

 cles absent. 



Here we have a partial precocious wart formation in the doubled 

 set£e on iii analogous to the condition in S. antigone but considerably 

 less developed, not affecting the thorax at all. I regard this species as 

 more specialized than the preceding chiefly on account of the fusion of 

 tubercles iv and iii, a condition found also in some of the Lymantriidse, 

 a high type in another line of evolution. 



Halisidota caryae. 



Tubercle iv unconnected with iii, but iii doubled as in H. maculata. 

 On segments i to 8 subprimary tubercle vi is present. No subprimaries 

 on thorax, but iia partly fused with i on mesothorax ; otherwise normal 

 as in ^S. virginica. 



This larva exhibits a partial precocious wart formation and a partial 

 appearance in stage I of the subprimary tubercles. It therefore shows 

 an incompletely developed combination of the characters of Hyphantria 

 cunea and Spilosoma antigojie and is consequently higher than either. 

 It is more advanced than H. maculata in the presence of the sub- 

 primaries. 



Cosmosoma auge. 



Tubercles weak ; setge single, normal, no subprimaries. This larva 

 is placed higher than all the preceding on account of the complete. 



