1905 - 6 .] Collembola from the South Orkney Islands. 
483 
Fig. 15, Cryptopygus crassus, ocelli and post-antennal organ of 
right side of young individual (fig. 13), x 150. 
Fig. 16. Do. ocelli, post-antennal organ ( p.a.o .), feeler, and 
antennal organ (a. o .) of right side. Adult male, x 150. 
Fig. 17. Do. hindmost foot, with claws, x 200. 
Fig. 18. Do. right mandible, ventral view ; ap., apical teeth ; 
mo., grinding surface; hu ., external shoulder ; x 200. 
Fig. 19. Do. right maxilla ( mx .), maxillula ( mxl .), and 
tongue ( tin .), ventral view ; ga., galea ; la., lamellae ; pa., palp ; 
rh. int., internal chitinous rod; sti., stipes; car., cardo; yd., foot 
of tongue ; lig., ligament of tongue. The left maxilla and left 
half of the tongue have been removed to expose the left maxillula 
(mxl.), with its supporting arm ( br .), and ligament (lig.), x 200. 
Fig. 20. Do. right mandible, viewed from inner aspect ; ap., 
apical teeth ; mo., grinding surface ; pro., dorsal process, x 200. 
Fig. 21. Do. dens and mucro of spring, adult specimen, side 
view, x 250. 
Fig. 22. Do. spring, half-grown individual, x 250. 
Fig. 23. Do. spring, very young individual (fig. 13), x 250. 
(. Issued separately January 14 , 1907 .) 
