REVIEWS OF NEW PUBLICATIONS. 
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an unfailing test of mental power. Even so it is with zoological systems. One 
part depends upon another; and therefore even a subordinate part might form a 
character for an artificial system; but many absurdities would be involved in 
carrying it out; while by attention to the most important characters, or to the 
whole combined, comparatively little difficulty would be experienced, and the 
result would be a far more perfect arrangement. In Molluscology, however, as 
in other branches of Zoology, we are not always allowed our choice in this respect, 
for many species of shells, both recent and fossil, are never found with the animals 
which once resided in them. The naturalist must, therefore, be fully prepared to 
classify much of his material with more scanty data than he would desire. 
Systems have been formed from the consideration of the habits of mollusca, of their 
external or internal plates, called shells ^ from the inhabiting animals , and from the 
combination of these characters. 
The genus Bulla of Linn^us, with a few of his Murices , constitute the generic 
group Pgrula of Lamarr. Now this latter name is familiar to our readers as a 
genus in Ornithology. In instituting new names, care should be taken that the 
appellation is not already occupied in any branch of Zoology. In the present case 
perhaps it may not be worth while to alter the name; but the Coalhood’s scientific 
designation might be spelled as at present, Pyrhida (which we take to be the 
proper method), and Lamarr’s genus might also remain Pgrula. The distinction, 
it is true, is slight; and naturalists are not always careful in correcting their proofs ; 
but it appears to us the smaller of two evils. And here, as we have entered upon 
the subject, let us notice another circumstance, which, though not of first-rate 
importance, yet, as it is often overlooked, may as well be alluded to. It is the 
plan of prefixing the article to Latin names, as “ the Clio Borealis ,” “ the Helix 
pellucida” &c. In Latin the substantive includes the article; and therefore “ the 
Argonauta Arctica” is just as absurd as “the VAigle tachete ,” “the VAquila com¬ 
mune” “ the die Sperber or “ die the Sparrow Hawk,” in French, Italian, and 
German. Want of attention to this gives ;a slovenly air to a scientific work. Nor 
ought we to pass in silence the typographical errors which disfigure this volume ; 
the odium of which may probably be divided between the Rev. Dr. Fleming and 
the “ Printer’s Devil.” 
At the conclusion of his retrospect of molluscological systems, our author ob¬ 
serves, that the reader, perhaps, is astonished at the changes which have taken 
place since the arrangement of Linn as us reigned paramount; and adds, very 
justly, that the Linnsean genera, though in general sufficiently numerous and 
commodious to embrace all the then known species, are perfectly inadequate to 
contain the greatly-increased number now familiar to the naturalist. The im¬ 
plicit followers of Linnaeus, in still retaining his genera, without the necessary 
additions, act in a manner which their great master, if now alive, would certainly 
