xlv 
in the eighth volume of the third series of the ' Naturhistorisk 
Tidsskrift' for 1873. To the old genera Gonjdeptes, Opilio, 
and Trogulus, are added three new genera, Anelasma, Amopaum, 
and Dicranolasma. 
The very remarkable structure and singular sexual differences 
in one of the parasitic Acaridre, at various stages of its existence, 
have been described and admirably figured in great detail, by 
Dr. Ehlers, of Erlangen, in ' Siebold und Kolliker Zeitschr. f. 
Wissensch.' (Zool. vol. xxiii.). The species belong to the Sar- 
coptidie, and are named Dermatorj^ctes mutans and fossor. 
The most important entomological work which has appeared 
during the past year is Sir John Lubbock's ' Monograph of the 
Collembola and Thysanura,' published b}^ the Ray Society. The 
latter of these two terms is confined to the Lepismidse, whilst the 
Poduridfe are regarded as of sufficient rank to be considered as a 
distinct order, " more nearly allied to the Insecta than to the 
Crustacea or Arachnida, although they cannot in the strictest 
sense be regarded as true insects," thus negativing their relation 
with the Orthoptera and Neuroptera.* The structure of the 
mouth of the Poduridse (Collembola) is carefully examined (as 
indeed it had already been in the author's four memoirs, published 
in the Transactions of the Linnean Society), from which the 
author assumes that their cibarian characters are intermediate 
between those of the Mandibulata and Haustellata. The volume 
is divisible into two portions : an Introduction of one hundred 
pages, containing a review of the previous literature of the group ; f 
the classification and general description of the animals composing 
the two groups ; and an enquiry into " The importance of the 
Collembola and Th^'sanura in relation to the Evolution of the 
Insecta." These remarks, extending to fifteen pages, will be read 
with great interest, especially by believers in the Darwinian 
theory, which I need hardly say I am not able to adopt. The 
second portion of the work, extending to one hundred and fifty 
pages, contains the description and technical characters of the 
* Sir John Lubbock's views of their relations with the Myriapoda and Arachnida 
are rendered doubtful by a strange typographical blunder in p. 38. 
+ The complaint that only two British species of Collembola had been casually 
mentioned in English works, namely, Podura plumbea and Smynthius fuscus, in 
Samouelle's Compendium, might have been lessened, had the author been aware of 
my articles on several species in the ' Gardener's Chronicle.' 
