EOESEL VON ROSENHOP 297 



Eoesel distinguislies another Dytiscus, of which he 

 says no more than that it is very like the first in all its 

 stages. He then goes on to describe and figure the 

 Cybister (since been named after him) and an Acilius. 



The last of the water-beetles which Eoesel describes is 

 what we now call Hydrocharis caraboides, for which he 

 has no more convenient name than "the middle-sized 

 black water-beetle with convex back." Of this he gives 

 a full and interesting account, the best which I know.^ 

 He tells us that long after he became acquainted with 

 the full-grown beetle its larva and pupa remained un- 

 known to him. One day, while peering into the water 

 of a ditch, he saw a new insect-larva, which had several 

 pairs of feathered appendages sticking out from the seg- 

 ments of the abdomen. He brought it home, inferred 

 predatory habits from the form of the mouth-parts, 

 and succeeded in keeping it alive until it underwent its 

 transformation, when he discovered that he had been 

 rearing a Hydrocharis. His account gives hints which 

 would be useful to any modern investigator of an aquatic 

 insect of unknown habits. 



The Goat-moth 



So much of the Insecten-Belustigungen is occupied 

 with life-histories of Lepidoptera that it seems indis- 

 pensable to give a specimen of them. The Goat-moth 

 has been chosen because Eoesel's account of the natural 

 history forms an excellent complement to Lyonet's 

 anatomical memoir of the same insect.^ 



Eoesel has no name for the Goat-moth {Cossus 



1 Hydrocharis caraboides had been described by Swammerdara. See his 

 dedication of De Bespiraticme, his Hist. Insect. Qen., p. 144, and his Biblia 

 Nat., p. 286 and pi. xxxii, 5. 



^Vol. I, Sammlung iv, pp. 113-128, pi. xvii, xix. Roesel'a account of the 

 Puss-moth larva is cited infra, p. 306. 



