Bibliographical Notices. 353 



general introductory remarks to each order have been prepared. We 

 have already given a translation of those on the order Fungi, from 

 which our readers may judge of the information to be derived from 

 them : nor has the excellence of this particular portion been appre- 

 ciated only in England, for it has been translated into German and 

 Italian, and a Spanish version is now in the course of publication ; 

 indeed it may be pronounced almost a complete repertorium of my- 

 cological facts, and these put forth with a clearness and precision 

 which is very rare. Nor will those who are more especially inter- 

 ested in other portions of cryptogamic botany find less to interest 

 and instruct. 



The class Algas is taken in a very wide sense, as including the 

 three families of Phycece, Byssacece, and Lichenes ; and the author's 

 reasons for this distribution, which accord with those of Fries, are 

 detailed in a manner which cannot fail to be attractive. The con- 

 siderations on Byssacece, a very difficult and anomalous tribe of 

 plants, though short, are especially worth attention, and the illustra- 

 tions of the genera Collema and Leptogium, which accompany them, 

 are more complete than any that have hitherto appeared, and show 

 such a difference of structure between these genera and Lichens, 

 which to the external eye they so closely resemble, as would surprise 

 any one who has not paid a close attention to the composition of the 

 thallus in these curious productions. In fact, in these plants the 

 cortical and medullary strata are confused, and the gonidia, which in 

 Lichens are confined to the cortical stratum, are in consequence 

 dispersed through the gelatinous mass : thus they hold a place ex- 

 actly intermediate between Phycece and Lichens. It is probable 

 indeed that some plants usually referred to Byssacece, asThamnomyces, 

 are in reality Fungi, and we are inclined to think that Dichonema is 

 in the same predicament : in this genus, as in Cora, the reproduc- 

 tive bodies will, we venture to predict, be found seated upon spo- 

 rophores. Coznogonium again is so completely a Biatora with a fila- 

 mentous thallus, that we cannot help thinking that mature consider- 

 ation will remove it from Byssacece, an unfortunate and inexpressive 

 name ; and thus the class will form a natural division, consisting of 

 such genera as Collema, Leptogium and Lichina. 



As regards the general execution of the work, the number of new 

 and interesting species described, the beauty and correctness of the 

 plates, the fullness of the analysis, and the ability and tact displayed, 

 we cannot speak too highly. We know not that any work on natu- 

 ral history can be pointed out which can at all compete with it ; and 

 though the number of new species is considerable, the author has 

 exercised the greatest caution in proposing them as new, and not till 

 after a complete examination of all available information, and the 

 submission of specimens before publication to those whom he con- 

 sidered as most competent to give information. Since the pub- 

 lication of the work, a comparison which we have been enabled to 

 make with authentic specimens of Swartz in the Herbarium of the 

 British Museum has enabled us to make two corrections, which the 

 excellent author will be the very first to appreciate. His Polyporus 



