22 Transactions of the Society. 



the epidermis, that immediately below it were a number of mites 

 corresponding exactly to those which lliley found on the bark of 

 the apple : there was not here however any Coccus or other small 

 creature for the Acarus to destroy, and it manifestly was destroy- 

 ing the reed, and not anything else ; which process it was effecting 

 by eating its way along under the epidermis, leaving small furrows 

 behind it filled with dust, excremental matter, A:c. It was in 

 considerable numbers, and evidently in a locality which suited it. 

 I secured plenty for observation, and for breeding from, transferred 

 these into a breeding-cell without other Acari, and eventually 

 succeeded in tracing the whole life-history subsequent to the 

 hatching of the egg. The greater number of specimens, as is 

 usual in the family, were either nymphs or adult females, which 

 latter appear to correspond in every respect with Eiley's descrip- 

 tion and figures, which however are not very detailed, but with 

 them I found, in lesser numbers, and I subsequently also olitained 

 by breeding, a smaller Acarus which was evidently the male ; it 

 was interesting to find that this creature possessed the exceptional 

 character of the male of Kramer's T. Carpio, although with such 

 variations as might be anticipated in a different species ; thus the 

 thin chitinous plate or shelf projecting from the dorsal level of 

 the hinder end is present and strongly developed, but its 

 posterior margin, instead of being cleft into four lobes like 

 T. Carpio, is even and unbroken, although, oddly enough, four 

 long hairs, which arise from the under side of the plate a little 

 within the posterior margin, and are directed horizontally back- 

 ward, show through the semi-transparent chitin, and, by trans- 

 mitted light, somewhat simulate clefts in appearance. The large 

 protrusile suckers placed on the vertical part of the abdominal 

 margin, one on each side of the anus, are also present, and of large 

 size, so that the creature may fairly take its place as a close ally of 

 Dr. Kramer's species. 



Another surprise awaited me : among the Tyroghjphi were a 

 num])er of Hypopi which I naturally suspected to be the hypopial 

 nymphs of the species, a suspicion subsequently rendered a 

 certainty by breeding the Uyjyojjus from the Tyroglyphus nymph 

 and by securing specimens and preparations of the Tyroglyphus 

 nymph with the Ilypopus inside. One of these is shown at fig. 8, 

 which was carefully drawn from the life ; the state figured being 

 that shortly before the Hypopus emerges ; the ordinary nymph 

 being now little more than the cuticular parts, and the Ilypopus 

 being fully formed, and capable of considerable motion ; it draws 

 itself forward and backward within the nymphal skin, which is 

 much longer than the hypopial form, moves its legs, and otherwise 

 exhibits manifest signs of litie. All thisi! might have anticipated 

 from analogy ; but what I could not have foreseen was that this 



