DEVELOPMENT AND IMMATURE STAGES. 133 



epimera of the first and second pairs may be joined 

 together. Garpoglyphua is a good example of this; 

 illustrations of the undersides of both larva and adult 

 are given to show it. 



In those members of the genus Glycyphagus which 

 have strongly plumose or palmate hairs on the noto- 

 gaster, such as G. Canes trinii, G. plumiger, and G. 

 palmif&r, these hairs in the larva are scarcely plumose 

 or palmate at all. A careful examination with a 

 microscope will disclose a tendency to be slightly 

 villous, but that is all ; this fact produces a much 

 more striking difference in the general appearance 

 of the larva and the imago than is usual in the family. 



The Iarva3 of the Tyroglyphidse are generally almost 

 colourless and semi-transparent; exceptions to this 

 rule exist, however, in the case of Hericia Robini and 

 some other species ; moreover, in cases where the whole 

 dorsal surface is hairy or spiny, such as Glycyphagus 

 platygaster, the hairiness or spininess of that part is 

 ordinarily far less marked in the larva than the adult. 



The period of larval life is short, and the creature 

 does not increase in size very greatly during this stage, 

 although it does increase ; at the termination the larva 

 undergoes an ecdysis (its first), and that brings it to 

 the nymphal state. The ecdysis is preceded by a short 

 inert period, which, however, is not usually so long as 

 in some other families of Acarina e. g. the Oribatidae. 



THE NYMPH. 



In the Tyroglyphidse the nymph usually greatly 

 resembles both the larva and the imago ; but the 

 younger nymph before the first ecdysis is generally 

 most like the larva, while toward the end of nymphal 

 life the creature is more similar to the adult; where 

 the sexes of the imago are very dissimilar it is most 

 frequently the adult female that the nymph resembles 

 most closely. 



