40 PACKARD, NOTES ON 



spines which are very closely united terminate the obtuse tip of 

 the abdomen, and are no doubt homologous with the supraanal 

 plate of the larva. 



The surface of the pro-thorax and abdomen is finely punc- 

 tured. The color of the pupa is a uniform dark shiny mahogany. 



Length, .65 ; breadth, .20 inch. 



While the form of the pupa of Arctia Isabella is almost iden- 

 tical in its general outlines and proportions with Ctenucha, 

 there are still important differences which it will be interesting 

 to notice. The head parts are less distinctly marked ; the 

 vertex and clypeus are broader ; the antennae and legs are very 

 much shorter, not reaching to the ends of the wings, which meet 

 in front of them, and are united at their tips by a distance 

 equal to the length of the fourth abdominal ring. The wings 

 of Arctia have the outer edge very much less oblique than in 

 Ctenucha, the thorax is much longer throughout ; the female 

 genital armor is the same, though the ninth ring is longer, and 

 the supraanal spine is a large flattened single stout spine, its 

 edges terminating in two slender small spines. 



One imago died just as it was breaking through the pupa 

 case, affording a means of ascertaining the mode of exclusion of 

 the imago. The meso-scutum was split widely apart, throwing 

 the pro-thorax with the head and its mouth-parts forward and 

 downwards ; this act likewise forced outwards and downwards the 

 wing, thus allowing the feet and wings of the immature imago to 

 become exposed to the air long enough to harden, and thus serve 

 to aid the moth in freeing itself from the rest of the body, which 

 remains whole, after the moth has escaped from it. The 

 antennae were also drawn out and extended in front of the head ; 

 to effect this, the eyes of the pupa were evidently separated 

 from the pro-thorax, thrust downwards by a space equal to the 

 width of the antennae, which were then enabled by the splitting 

 asunder of the antennae and wings of the pupa, to be extended 

 forward. 



By the pectinations of the antennae, the specimen is evidently 

 a female, its genital armor agrees exactly with that of the pupa 

 above described, so that the sexes of the two are the same. 



The hairs of the body within the pupa case are the same in 

 density and coloration as in the mature moth. 



SCEPSIS Walker. 

 The head is larger in proportion to the rest of the body than 



