304 The Ohio Naturalist. [Vol. Ill, No. 1, 



borne between the claws, and also a prolongation of the last seg- 

 ment called the pulvilliis. The tibial joint opens forward in the 

 first pair of legs and backward in the second and third pairs. The 

 trochanter lies on the anterior surface of the first pair, but on the 

 posterior surface of the last two pairs. By comparing this leg 

 with the last two it will be seen to be rotated forward, that is, 

 structures on the posterior surface of the first leg are on the an- 

 terior surface of the last two pairs. 



The trochantin is situated on the outer end of the coxa. It 

 is convex and presents three faces, an outer or lateral, which is 

 smooth ; an inner or dorsal, which furnishes attachment for the 

 dorsal muscles, and a ventral face, which furnishes attachment 

 for the ventral muscles. It is articulated by its posterior border 

 with the coxa and lies in a depression of the anterior arm of the 

 coxa below and in front of the point of articulation of the coxa 

 with the body wall. 



The jugular sclerites (13) are small pieces lying between the 

 posterior ventral portions of the head and the anterior portion of 

 the pro-thorax. The anterior surface is concave and smooth. It 

 articulates with the head and is attached to it on its ventral inner 

 border by a strong ligament. The ventral portion of the posterior 

 surface is smooth and protrudes from under the pro-thoracic ster- 

 num. The dorsal two-thirds of the posterior surface is rough 

 and bears a posteriorly directed process which gives off a ventral 

 keel and a lateral one which runs to near the inner border. 



The meso-thoracic spiracle lies on the hinder border of the 

 coxa in the membrane connecting the coxa to the posterior border 

 of the pro-sternum and epimeron. It is not visible from the ex- 

 terior but can be seen by removing the coxa. It is very large, 

 being about four millimeters in length. 



THE MESO THORAX. 



This segment articulates anteriorly with the pro-lhorax and 

 is fused posteriorly with the meta-thorax. It is much narrower 

 than either of these segments and bears on its dorsal surface a 

 strongly chitinized elytra or wing cover, and on its ventral sur- 

 face the second pair of walking legs. The meso-thoracic tergum 

 of some beetles contains four sclerites, the prescutum, scutum, 

 scutellum, and postscutellum. Tlic prescutum and postscutellum 

 are frequently wanting. 



The scutellum (6) lies on tlie mid-dorsal line of the meso- 

 thorax. It is triangular with the base of the triangle directed 

 forward. It is free in front, and laterally is continued under the 

 triangular base of the elytra in a less chitinizctl area which finally 

 is continuous with the articular meml)rane of the elytron. Pos- 

 teriorly it is fused with the postscutellum. Tlie postscutellum (7) 



