350 



Consequently a complete parallelism exists between these groups. 

 Of course another arrangement may also be conceived, in which 

 the "horned" ones are placed together. 



In this case, however, difficulties woiild be met with in regard 

 to the warts. 



The SYSSPHINGINA descend from forms (Packard 1 905, p. 44) 

 which bear tubercles not producing more than a single setae. The 

 primary groups of the Notodontidae viz. Xotodotifinae, Heterocam- 

 pinae and Cemnnae have already been discussed with the family. 



Family Cercdommpidae. Two of the three volumes of Packard's 

 work have been devoted to this family. Of a great many cater- 

 pillars complete descriptions are given (1905 — 1914). 



The caudal horn deserves to be specially mentioned. In Adelo- 

 cepJiala it has arisen [as is clearly visible in Packard's figure, 

 1905, PI. XLV, fig. 3] from the s. dorsalis of segment 8. 

 It ends in two setae, exactly as in the Sphingidae. On the meso- 

 thorax and the metathorax too, the s. dorsahs have increased 

 enormously and are bifurcated. The ordinary setae change diiring 

 the following instars into spinose ones, whilst the caudal horn 

 loses the two setae at the end and then forms one single, purely 

 median projecting part. 



Syssphinx and Eacïes have the same ontogenesis. In Ani- 

 sofa a median dorsal horn is developed on the metathorax from 

 the s. dorsales and a median tuberculum on the 9tli abdominal 

 segment apparently from the s. suhdorsaJes. Citheronia has many 

 setae developed into large scoli, as well on the thoracic as on the 

 last abdominal segments. 



Except in the Ceratocamjndae these scoli only occur on the 

 Hemileucidae, the Saturnüdae^ the Nyiuphalidae and the Heli- 

 comidae. Packard thinks with Fracker (1915, p. 120—126) that 

 this is of great importance and I am inclined to agree with them. It 

 seems to me that tlie dorsal horn on the 8tli abdominal segment 

 too is of great importance in judging of the relationship. The 

 number of the scoli varies greatly, secondary setae may be found 

 or not. See Fracker (1915, p. 121—123). 



