424 A^tnals Entomological Society oj America [Vol. XI, 



vSubfamily Smerinthin^e. 



There are but three American genera belonging here, 

 Smerinthus (including Paonias), Pachysphinx and Cressonia. 

 These differ from all other sphingid pupae in the possession of 

 short maxillae and broader antennae than is usual. They 

 approach more nearly to the saturnian type of pupa, and many 

 of them have been reported as spinning cocoons. The labrum is 

 in the position normal to all lepidopterous pupae. They show no 

 trace of the prothoracic femur and are in that respect more 

 specialized than most of the Archerontiina^. The eye-pieces are 

 very like the preceding subfamily except that they usuall}^ 

 touch at one point. The antennee vary in the sexes being longer 

 and wider in the males. The spiracular furrows which are three 

 or four in number, punctate, and separated by interrupted 

 ridges, are almost identical in all of these pupae except Cressonia, 

 which has only one deep spiracular furrow, thus showing kinship 

 with the Acherontiinae. Cressonia is not very closely related in 

 many respects to this group, and seems to be a rather aberrant 

 form. Its maxillae and antennae, however, show that it belongs 

 here. 



Genus Smerinthus Latr. 



It has been impossible for me to find any characters which 

 will serve to separate the genus Smerinthus from Paonias, so all 

 species have been included under one generic name. The 

 species are so extremely variable that it is impossible to give a 

 species description which will fit all the individuals, and makes 

 it exceedingly difficult to separate them. The head, thorax and 

 appendages are somewhat roughened with impressed lines, and 

 the abdomen has both punctures and impressed lines, yet in 

 most cases the body presents a polished appearance. The 

 labrum is always on the ventral surface. The "maxillae are short, 

 only about one-third the length of the wings and there is no 

 maxillary loop. The antenna are fairly constant in length in 

 most of the species. They are a little shorter and narrower in 

 the female than in the male. In the female their greatest width 

 is about equal to that of the prothoracic legs. Both prothoracic 

 and mesothoracic legs as well as the metathoracic wings meet 

 on the meson caudad of the maxillae. The thorax usually has a 

 slightly elevated median line, most prominent on the meta- 



