294 



ROBERT S. BREED AND ELSIE F. BALL. 



3. The metathoracic groove widens in its anterior portion, so 

 that the entire groove has the form of a Y with its arms project- 

 ing forward. The triangular scutellum Hes in the opening be- 

 tween the arms of the Y. In closing the elytra, their anterior 



Fig. 6. Similar to Fig. 5. Right elytron. X 75- 



edges slip under the diagonal edges of the scutellum and hook 

 over the ridges made by the diverging arms of the Y. The 

 thickening along the edge of the elytron at this point has still 



Fig. 7. Cross section of the lateral edge of the right elytron of Lachnosterna. 

 X150. 



more the form of a hook than those shown in Figs. 3 and 4. 

 The interlocking is therefore very firm in this region, especially 

 as the downward pressure of the scutellum aids in resisting any 



