Bibliographical Notices. 299 
body when diving, instead of which the peritrema of the spiracles in 
Helophorus is dilated and so arranged that a small quantity of air will 
adhere to it. In the larve of Hydrophilus the lateral appendages 
of the abdomen are soft, flexible, ciliated, and assist in buoying up the 
heavy fleshy body of the larva (for which purpose even the antenne 
are ciliated); but they do not serve for respiration as in the 
larvee of Berosus, where they form true branchie of considerable 
size. In this last genus the terminal (eighth abdominal) pair of 
spiracles, which in the family of Hydrophili are usually very large 
and lead into a capacious air-chamber, are accordingly very minute, 
and the air-chamber is wanting. In the larva of Hydrous these 
lateral appendages are very small; and they are entirely wanting in — 
the larvee of Hydrobius and of Philhydrus, which simply walk about 
on submerged objects, the latter even assisted by five pairs of abdo- 
minal feet. In the larve of Cercyon and Spheridium, which re- 
present the Hydrophiline type modified for life on dry land (though 
in humid places), we find neither lateral abdominal appendages nor 
even true feet, the animal wriggling its way through the deébris 
amongst which it lives, whilst the last abdominal segment is the 
largest of all, and often armed with hooks. In the family of Sta- 
_ phylini a remarkable division presents itself, separating the family 
into two main parts,—one of which comprises the typical forms of 
the family, the group of Staphylinini ; whilst the other embraces all 
the remaining groups, of which, however, only Oxytelini find a 
place in the portion of the memoir as yet published. But regard to 
space forbids our extracting more details or entering upon the ge- 
neral considerations which are largely suggested by the contents of 
_ this memoir, of which the above gives but a very inadequate idea ; 
and we shall only add that nothing can be more varied than the 
succession of beings represented on the plates, or more instructive 
than the mode in which the author has handled the enormous mass 
of new and interesting details which he has observed. 
In his present paper on Stalita (vol. iii. p. 70), Prof. Schiddte 
recurs to an observation made by him in a paper on the classifica- 
tion of Cerambyces, in Nat. Tids. ser. 3. vol. ii. p. 483 (Ann. & 
Mag. Nat. Hist. ser. 3. vol. xv. pp. 182, 183), to the effect that 
Arthropoda exhibit analogous variations with regard to the man- 
ner in which they tread the ground to those observed amongst 
Vertebrata, especially Mammalia; so that amongst them, too, we 
find plantigrade, digitigrade, and unguligrade groups, which are dis- 
tinguished by analogous modifications in the development and outer 
appearance of the different parts of the limbs. ‘The true key,” 
says he, “to the differences in structure between the leg of an inseet 
and that of a spider, to the manner in which the respective divisions 
of the leg participate in the building up of the limb, and to their 
relative position, size, and shape, lies in the circumstance that spi- 
ders are digitigrade. If we thoroughly appreciate this, we shall 
also admit that the nomenclature now in use is faulty. In order to 
enable the spider to tread on the under surface of the point of the 
foot, that part of the leg which is outside and below the knee re- 
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