GENUS DOLERUS. 159 



by the form of the head, by the amount of puncturing 

 on it and on the thorax, by the form of the thoracic 

 sutures, of the neuration, and of the ovipositor. As 

 regards punctation it cannot always be depended upon, 

 for it seems to vary in intensity in the same species. 

 By the form of the head in wanting sutures on the 

 vertex -fissus, oUongus and megaptera are readily 

 separated from the other species. Another well- 

 marked group is formed by cor acinus and anthr acinus 

 distinguished alike by the smooth, shining, almost 

 impunctate body, and by the suture bounding the 

 middle lobe of the mesonotum being semi-circular at 

 the apex, while with the other species it is triangular, 

 and their mesonotum is punctured almost throughout. 

 There can be no doubt that the form of the ovipositor 

 can be safely relied upon in separating the species, but 

 it is not always easy of application. The black species 

 should always have their saws extended in such a way 

 when the insects are fresh that they can be examined 

 by the microscope a procedure which will save 

 much trouble in naming the species afterwards. The 

 position of the nervures may, within certain limits, be 

 depended upon, but no great reliance can be placed on 

 the colour of the spurs, though this was a character 

 relied upon by Hartig for discriminating species. It 

 only remains to add that the form of the body is apt 

 to change, owing to the abdominal segments shrinking 

 in. This causes sometimes the abdomen to bulge out 

 at the sides and become depressed on the back. With 

 age, too, the nervures become paler. 



Synopsis of Species. 



1 (4) Eyes oblong, inner orbits margined ; tegulao and labram white ; 



abdominal segments in both sexes, or in <J only, marked 

 with white membranous spots. Parapsides not dilated 

 behind > 



2 (3) Legs black ; the anterior knees and base of tibia) dirty white. 



Palmatus. 



3 (2) Legs for the greater part red. Vestigialis, 



