298 
ON GLYCIPHAGUS DOMESTICUS AND G. SPINIPES. 
from it, while the Hypopus is still within the young nymphal 
skin ; so that the Hypopus is not ever seen, except that, in a 
few instances, it may crawl just outside the young nymphal skin 
when the more advanced nymph is likely soon to emerge. 
7. That in G-. domesticus the Hypopial stage is even more rudi- 
mentary ; what represents the Hypopus retaining only the general 
form of that creature, but being without legs or other external 
organs, and that it never emerges from the young nymphal skin. 
8. That in both species the young nymphal skin within which 
the Hypopus is developed thickens and forms a “case” different 
in appearance from the skin during ordinary ecdysis. 
EXPLANATION OF PLATE XYI. 
Fig. 1. Glyciphagus domesticus : adult female, underside; X 95. 
2. Ditto: “case” containing the inert mass (very rudimentary Hypopial 
condition) ; X 150. 
3. Ditto : a portion of the cuticle of the “ case,” to show the vermiform 
markings ; X 200. 
4. Ditto : posterior end of “case” from which the nymph in its last stage 
has emerged ; side view, to show the mode of opening. 
5. Ditto : fourth left tarsus of adult female from above ; X 200. At the 
side is a liue showing the extreme width of the abdomen ; same 
amplification. 
6. Ditto : claw and caruncle from below, drawn from the living foot when 
pressed by the creature against glass ; X 500. 
7. Ditto : bursa copulatrix ; x 200. 
8. Glyciphagus spinipes \ “ case ” containing the Hypopus ; x 150. 
9. Ditto : Hypopus dissected out of the “ case”; X 180. 
10. Ditto: a portion of the cuticle of the “case,” to show the reticulated 
markings ; X 200. 
11. Ditto: posterior end of “case” from which the nymph in its last stage 
has emerged ; seen from above, to show the mode of opening. 
12. Ditto: fourth left tarsus of adult female from above; X 200. At the 
side is a line showing the extreme width of the abdomen; same 
amplification. 
13. Ditto:' part of the third left leg of adult female from the outer side ; 
X 250. 
14. Ditto: hair from the second joint of the same leg; X 500. 
15. Ditto: bursa copulatrix. 
