298 



Oy GLTCIPHAGH7S D0MESTICU8 AND G. SPINIPES. 



from it, ^^hile the Ht/popus 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 njmphal skin 

 when the more advanced nymph is likely soon to emerge. 



7. That in Cr. 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 XVI. 



Fig. 1. Glyciphag us 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 "ease" 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 line 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. 



