NO. 13 



STAPH YLINIDAE BLACK WELDER 



51 



ture, or, if this suture is absent, approximately by a line drawn be- 

 tween the anterior tentorial pits. Since in these forms the frontal 

 sutures unite to form a nearly straight line, it is obvious that the true 



Fig. II. — Intrafamily variation in the form and structure of the 

 dorsal aspect of the head (continued from fig. 10). 



A, Tanyrhinus siiigiilaris Mann. B, Hesperobmm paUipcs (Grav.). C, 



Philonthus aciicus (Rossi). D, Oxyponis lateralis Grav. E, Metoponciis varians 



Shp. F, Bolitobius cinctus (Grav.). G, Acylophorus flavicollis Sachse. H, 

 Osorius mundus Shp. 



frons is undifferentiated from the other parts. The area anterior to 

 the tentorial pits is therefore the postclypeus. A portion of the hy- 

 postomal suture or epicranial arm is sometimes present, extending 



