This insect is nearly allied to Geom. Spartiata and ohliqiiata 

 and is included with them and many other incongruous spe- 

 cies in the genus Chesias by Treitschke, but their palpi and 

 legs are differently formed. 



The early states of Pachycnemia are unknown, but from 

 the specific name of Hippocastanaria, Hiibner must have sup- 

 posed that it was an inhabitant of the horse-chestnut tree : 

 M. Duponchel however is of opinion that it is attached to the 

 Spanish chestnut, as he has never found it excepting in woods 

 where that tree exclusively grows ; in England it seems to fre- 

 quent heathy districts, and I think it has been taken very far 

 from either of those trees by my friend Mr. Dale. 



It is rather of rare occurrence in this country, and few 

 moths vary more in the time of their appearance : a female was 

 found as early as April on Ockham Heath in Surrey, but 

 Mr. Dale has taken specimens from the 25th of March to the 

 beginning of September on Parley Heath, Hampshire, and in 

 the New Forest where it is most abundant in July ; it has also 

 occasionally been met with near Birch Wood in Kent, and at 

 Rochford in Essex. 



Hiibner's figure of G. degenerata is no doubt drawn from a 

 wasted specimen of the female of P. Hippocastanaria. 



The Plant is Spartium (Cytisus Linn. ?) scopariiim. Com- 

 mon Broom. 



