556 GEOLOGICAL SURVEY OF THE TERRITORIES. 



EXPLANATION OF PLATE XXL 



Fig. 1. Lepidarus glaciaUs, female ; tenth appendage. 



Fig. 2. Lepidurus glaciaUs, female ; eleventh appendage, with ovisac. 



Fig. 3. Lepidurus bilohatus, female ; tenth appendage. 



Fig. 4. Lepidurus conesii, male; tenth appendage. 



Fig. .5. Lepidurus couesii, female ; tenth appendage. 



Fig. 6. Lepidurus couesii, female ; eleventh appendage. 



Fig. 7. Apus lucasanus, maxilla,. 



Fig. 8. Apus lucasanus, maxilla, seen from the inside. 



Fig. 9. Lepidurus couesii, maxilla. 



Fig. 10. Apus lucasanus, maxilla. 



Fig. 11. Lepidurus couesii, mandible. 



Fig. 12. Apus lucasanus, mandible. 



Fig. 13. Apus hicasanus, outside view of the same specimen as Fig. 8 represents. 



