30 Arachn. 
AKACHNIDA. 
organs, pp. 228-240 ; the different stages through which each individual, 
male and female, passes, pp. 228-240. The normal stages are, for males, 
four; for females, five : 1, egg; 2, hexapod larva; 3, octopod nymphs, 
without sexual organs ; 4, sexually perfect males, and immature females 
often wanting external genital organs, but capable of copulation ; 6, 
females sexually perfect and fecundated. Each of these stages is sepa- 
rately and fully discussed. Remarks are added on the moultings of 
Sarcoptidce, pp. 240-244 ; on the habitat of the plumicolce in general, 
pp. 245 & 246; and on their zoological affinities, pp. 246-248. Part ii., 
pp. 391-429, 498-519, & 629-656, characterizes and describes the genera 
(6 in number) and species (32), an analytical table being given, p. 392 : 
Pterolichus, C. Rob., 10 spp. ; Pteronyssus, C. Rob., 2 spp. ; Derma- 
lichuSf C. L. Koch, 11 spp. (9 of these last, however, are described 
further on under Analges, Nitsch, and 1 under Dermoglyphus^ C. Rob., 
p. 498, et seq.) ; Proctophyllodes, 0. Rob., 8 spp. (4 of which are included 
under the subgenus, Pterodactes, C. Rob.) ; Pterophagus, M^g. The 
greater number are figured ; none are new. 
[Mi^gnin, M.]. Mdmoire sur le Demodex folliculorum, Owen. J. Anat. 
Phys. xiii .(1877) pp. 97-^122, pi. ix. 
Treats at considerable length upon the bibliography and zoological 
position of this curious Arachnid. The genus is characterized, p. 110, 
and the species, D . folliculorum, with its varieties, horninis and cati, are 
described, pp. Ill & 112. Its anatomy and physiology are fully detailed, 
pp. 113-122. 
Robin, C. Note sur une iiouvelle espece de Tyroglyphe, le Tyroglyphus 
sironiformis. J. de PAnat. Phys. ix. pp. 435-438. 
Donn ADIEU, A. L. Sur un Acarien nouveau, suivi d’un essai d’une 
classification parallele de I’ordre des Acariens. J. de I’Anat. Phys. 
xii. pp. 595-602, pi. xviii. 
The species described is Heierotrichus inceque^armatus. 
