412 LEPIDOPTERA. 



ures one inch and a half or two inches in length, is of an 



amber color, changing to brown 

 Flg " 204 ' on the fore part of the body ; 



r 4 and on the upper side of each 

 QBt abdominal ring are two trans- 



^^ verse rows of tooth-like projec- 

 tions. By the help of these, the insect, when ready for its 

 last transformation, works its way to the mouth of its bur- 

 row, where it remains while the chrysalis skin is rent, upon 

 which it comes forth on the trunk of the tree a winged 

 moth. In this its perfected state, it is of a gray color ; the 

 fore wings are thickly covered with dusky netted lines and 

 irregular spots, the hind wings are more uniformly dusky, 

 and the shoulder-covers are edged with black on the inside. 

 It expands about three inches. The male, which is much 

 smaller, and has been mistaken for another species, is much 

 darker than the female, from which it differs also in having 

 a laro;e ochre-yellow spot on the hind wings, contiguous to 

 their posterior margin. Professor Peck, who first made 

 public the history of this insect,* named it Cossus Robinice, 

 the Cossus of the locust-tree, scientifically called Robinia. 

 It is supposed by Professor Peck to remain three years in 

 the caterpillar state. The moth comes forth about the mid- 

 dle of July. The same insect, or one not to be distin- 

 guished from it while a caterpillar, perforates the trunks of 

 the red oak. Mr. Newman f has recently given the name 

 of Xyleutes, the carpenter, to the genus including this insect, 

 instead of Cossus, which it formerly bore, because the latter, 

 being the name of a species, ought not to have been applied 

 to a genus. The European carpenter-moth, called Bombyx 

 Cossus J by Linnaeus, will now be the Xyleutes Cossus ; 

 and our indigenous species will be the Xyleutes Robinioe 



* See " Massachusetts Agricultural Repository and Journal," Vol. V., p. 67, 

 with a plate. 



t See "Entomological Magazine," Vol. V., p. 129. 

 % Subsequently named Cossus ligniperda by Fabricius. 



