16 



Atlantic coast to Delaware Bay. Inland they do not extend farther 

 north than West Virginia. The three species differ only in minute 



Fig. 4. — Ambrosia of Platypus compositus— greatly enlarged (original). 



details, and the habits are the same in all. P. compositus, represented 

 in fig. 2 (upper fig.), is perhaps our commonest species. 



They are not confined to any particular kind 

 of timber, and are as frequently found in con- 

 ifers as '" deciduous trees. 



THE GENUS COBTHYLUS. 



In tnis genus the form is short and stout, the 

 ihorax and abdomen are almost equal in size, 

 so that the body appears to be divided in the 

 middle. The surface is smooth and shining; 

 there are no engraved lines or rows of punc- 

 tures upon the wing cases, and the color is a 

 deep black. The sexes are alike. All the species 

 attack plants which are in perfect health. 



Cortliylus imnctatissimus Zimm. (fig. 5) is a 

 very common species in the forest region of the 

 Eastern United States. It attacks and kills 

 shrubs and young trees, such as maple, sassafras, dogwood, hazel, 

 ironwood, etc., and is also found in the roots of huckleberry. 



Fig. 5. — Gorthylus punctatissi 

 mus (original). 



