83 



Iinnu'diatt'ly after the moult on prothorax and segment 8 setae 

 which differ from the rest. The plumose ones shorter than the 

 ordinary setae in instar /// and IV. Those of segment 8 only 

 come in instar IV and are still very short. 



Whole life as caterpillar is 45 — 55 days. Four moults. 



I hope that these differences may give rise to new investigations. 



It also seems to me that the histological structure of these 

 setae and the manner of their origin within the more simply orga- 

 nized ones of the f«irmer instar, are worth while examining. 



I draw attention to the fact, that J. U. Kruimkl in his inves- 

 tigations on the feathers of the Gallinao (1916) also found a 

 more composite structure in the successive ^editions of feathers" 

 whifh apjM'ar after the different moults. 



Family Ijasiocampidae. Fracker (1915, p. 103) thinks there 

 are too many setae to be able to describe them. Some genera 

 are characterised by a dorsal horn on segment 8. 



Dyar (1893 h) has described different kinds. 



Lasiocamjxi nihi L., Plate II, fig. 6, 7. 



Material in alcohol of the three last instars of the cater- 

 pillars (i. e. instar ///, /F, F), collected at Groningen, in the 

 summer of 1913. 



Instar ///. Length 27 mm. 



The whole body is covered with widely spread setae of about 

 '/i mm. long. The tubercula are black, have the form of warts 

 and possess many unfeathered setae, which are about \^j^ mm. long. 



Prothorax. No prothoracic shield, but there is an elevation between 

 the three following verrucae. This elevation, however, is not black 

 and the setae are as large as on the remaining surface of the body. 



There are: v. dorsalis, r. subdorsalis, v. supraatig mails ^ placed 

 very high ; v. jirostigmalis, v. basalis, smaller v. pro2)edaUs and 

 r. postjiedalis. 



