Bihliographical Notices. 299 



body when diving, instead of which the peritrema of the sjiiracles in 

 Helopliorus is dilated and so arranged that a small quantity of air will 

 adhere to it. In the larvae of ffi/drophilus the lateral appendages 

 of the abdomen are soft, flexible, ciliated, and assist in buoying uj) the 

 heavy fleshy body of the larva (for which pui-pose even the antennai 

 are cUiated) ; but they do not serve for respiration as in the 

 larvae of Berosus, where they form true branchiae of considerable 

 size. In this last genus the terminal (eighth abdominal) pair of 

 sinracles, 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 larvffi of Htfdrobius and of Philhydrus, which simply walk about 

 on submerged objects, the latter even assisted by five pairs of abdo- 

 minal feet. .In the larvae of Cercyon and Splioeridium, 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 debris 

 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 inadeqiiate 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. Schiodte 

 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 insect 

 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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