102 HYMENOPTERA. 



it is acutely oval, and with five rings in the male. Ch'pte* 

 semia a, <!?<! La.tr. is found in Central Europe. AVe have no na- 

 tive species. In Chm/sis and the other genera, Stilbum, Parno- 

 pes, and Hedychrum, the abdomen is hollowed beneath, and 

 the tip is broad and square. CVov/.s/.s hi'lan's Dahlb. (Fig. 122) 

 is a short, thick, bluish green species, .32 inch in length. It 

 is not uncommon in New England. 



In Hedychrum the maxillary palpi and ligula are rather short, 

 the last cordate ; the mandibles are three-toothed within. The 

 abdomen is broad and short, almost spherical, the second seg- 

 ment being the largest. H. dimidiatum Say is found in the 

 Middle States. 



The European Stilbum splendidum, Fabr. according to l)u- 

 four, lives in the cells of Pelopanis spirifex. It makes oblong 



cocoons of a deep brown, with rounded 

 ends ; they are of great tenacity, being 

 mixed with a gummy matter. 



Mr. Guenzius states that in Port 

 Natal ''a species of ^tiJhiini lays its 

 eggs on the collected caterpillars stored 

 up by Eumenes tinctor, which con- 

 structs a nest of mud and attaches it to reeds, etc.. not in a 

 single, but a large mass, in which cells are excavated, similar 

 to the nest of Chalicodoma micraria?* First, it uses its ovi- 

 positor as a gimlet, and when its point has a little penetrated, 

 then as a saw or rasp ; it likewise feels with its ovipositor, and, 

 finding an unfinished or an empty cell it withdraws it immedi- 

 ately, without laying an egg." 



ICHNEUMONID^E Latreille. The Ichneumon-flies are readily 

 recognized by the usually long and slender body, the long ex- 

 serted ovipositor, which is often very long, and protected by a 

 sheath formed of four stylets of the same length as the true 

 ovipositor. The head is usually rather square, with long, 

 slender, many-jointed antenna 1 which are not usually elbowed. 

 The maxillary palpi are five to six-jointed, while the labial 



*A query (?) after the name of a species indicates a doubt whether the insect 

 really belongs to that species; so with a ? after the name of a genus. A '? before 

 both the genus and species expresses a doubt whether that be the insect at all. 



