NEMATUS CCERULEOCARPUS. 83 



anal cerci are dark brown. The food canal shines 

 through the skin as a dark stripe. At the last moult 

 the skin assumes a darker green colour. It is found 

 in the autumn. 



When young it eats holes in the leaves of poplars 

 and willows ; when more mature it feeds along the 

 edge, with the body curved to the shape of the part 

 it has eaten out. It spins a large, double, dark brown 

 cocoon in the earth, in which it pupates in April, or the 

 beginning of May, the imagos appearing in May and June. 



The pupa is glassy green, with the limbs paler and 

 the eyes black. 



Through these two species having been confounded 

 a good deal of confusion has arisen regarding their 

 synonyms. After the description of Fallen the next 

 earliest is that of St. Fargeau, who described one 

 of the forms under the name of vicinus, but whether 

 it refers to cceruleocarpus or to crassus cannot now be 

 decided, as he does not mention those points by which 

 the two are separated. The same remark might 

 almost be said of Hartig's description of cceruleocarpus, 

 yet as he says that the coxas are only black at the base, 

 and that the apex only of the hinder tibiae is black, while 

 in sulcipes the tibise are only red at the base, and, again, 

 as he states also that it is half a line shorter than sul- 

 cipes, there can I think be no doubt that cceruleocarpus 

 is the same as br achy acanthus, which name, therefore, 

 should not be adopted. Furthermore, it is certain that 

 it is br achy acanthus which Van Vollenhoven has 

 described under the Hartigian name. Zaddach treats 

 both forms as mere varieties of one species, adopting 

 the name of crassus (Schr. Ges. Konig., p. 353, 16) 

 on the ground that the points of distinction between 

 them are not of specific value, treating especially the 

 length of the spurs as a variable character not to be 

 depended upon. Taking, however, into account that 

 there is also a difference in the form of the saw, and 

 that as yet the larger form has not been bred, I do 

 not feel inclined to unite them. 



