-32 



NATURAL HISTORY BULLETIN. 



Head small, covered by the thorax when at rest, but 

 extended when the insect is in motion. 



Antenna four-jointed, the first three joints stout but gradu- 

 ally decreasing in thickness, the fourth verv short and thick. 

 All are bristly. 



Mandibles rather slender, very sharp, curved, the inside 

 with a double tooth bevond the middle. Near the base thev 

 are rather densely bristled internally and appear to be perforate 

 through the entire length as shown in the figure. 



Maxillae with a very large basal piece bearing internally a 

 bi-articulate appendage, the terminal joint of which is small. 

 The external portion is four-jointed, the first joint apparently 

 entirely membraneous, the second smaller, chitinized. the third 

 extremely short and thick, the fourth slender. These are all 

 more or less bristly. 



Mentum bilobed. palpi verv short, two-jointed. The sub- 

 mentum is elongate and bears two long bristles before the 

 middle. 



Prothorax rounded in front, finelv canaliculate at middle of 

 disk and slightly emarginate anteriorly. Disk uneven, rugose, 

 and with a large fovea on each side near the rounded posterior 

 angles. ^largin reflexed all around. 



Mesothorax broader than long-, sides reflexed. angles round- 

 ed. disk vaguelv canaliculate at middle, excavated and rough- 

 ened near the sides. ]SIetathorax similar to mesothorax. 



Abdomen of nine segments about equal in length, side 

 margins reflexed. disk elevated at middle, depressed and 

 roughened at sides. The eighth segment is luminiferous and 

 is more broadly white on the sides above than are the others. 

 The ninth is used as a prop-leg and is ordinarily bent nearly 

 at right angles to the others when the animal is in motion. 



Legs rather short, coxje prominent, the suture between the 

 femur and trochanter distinct, tibise shorter than femur, claw 

 single. All the joints are bristly except the claw. 



Several of these lar^ce were found together under the bark 

 of a decaying oak log about the middle of April and were 

 kept (refusing animal food offered them i for about a month 



