544 GEOLOGICAL SURVEY OF THE TERRITORIES. 
EXPLANATION OF PLATE XV. 
Fic. 1. Apus equalis Packard, 9 enlarged twice. la, upper; 16, under side of the tel- 
son enlarged. 
Fig. 2. Lepidurus couesii Packard, nat. size. 2a, side view of the same. 
Fic. 3. Lepidurus bilobatus Packard, nat. size. 
rawn by J. H. Emerton. 
