412 Bibliographical Notices, 



The figure of Botrydium granulatum is evidently a reversed copy of 

 part of Dillwyn's plate oiConferva multicapsularis , and yet Mr. Hassall 

 quotes that synonym doubtfully ; thus allowing that, even in his own 

 opinion, his figure may not represent B. granulatum. Why not state 

 this ; and also why not copy Greville's figure, which certainly repre- 

 sents the true plant ? 



We now come to the DesmidecB, to our mind the least satisfac- 

 tory part of the book, for we suspect that here the author is far 

 less at home than in the preceding families. A more prominent 

 reference might have been made to the very successful labours of 

 Mr. Ralfs upon this family, and also the Diatoinacece, which have ap- 

 peared in our pages, and are now published in a collected form in the 

 'Transactions' of the Edinburgh Botanical Society. From these 

 papers Mr. Hassall has avowedly transcribed the remarks on several 

 of the species, and has apparently copied by far the greater number 

 of the figures of the Bestnidece, He does state that ^' several of the 

 figures of this family, especially those of the genera Euastrum and 

 Cosmarium " are so obtained, but might have added, that nearly if not 

 quite every figure of Staurastrum, Scenedesmus, Pediastrum, Xanthi- 

 dium and Tetmemorus have the same origin. We do not blame him 

 for copying these beautiful drawings, but he ought to have taken 

 better copies, and also acknowledged his obligation to their author. 

 Nearly all the figures of Closterium we think are derived from Ehren- 

 berg ; the figure named CI. lunula is not that species, but a variety of 

 CI. Ehrenhergi. In this case an acknowledgement was the more 

 necessary, since it is more than probable that some of the figures do 

 not represent British species ; for instance, our CI. margarltaceum 

 differs from Ehrenberg's figure in not being granulated, and is 

 perhaps distinct ; Ehrenberg's CI. digitus is not the same as the spe- 

 cies so called in Britain. 



We cannot however afford time or space to hunt out and record 

 all these errors, nor indeed the very many erroneous references to 

 synonyms, but merely observe that Mr. Ralfs is frequently made to 

 have used a nomenclature quite different from that which really 

 exists in the * Annals ' and * Transactions' ; and that the references 

 to Mr. Jenner's * Flora of Tunbridge Wells ' are incorrect in nume- 

 rous cases. This is really too bad, as a very little ordinary care would 

 have prevented it. We readily forgive an author for mistakes, for to 

 them we are all liable ; but carelessness of this kind and to this ex- 

 tent is unpardonable. 



Mr. Hassall justly remarks, that our knowledge of these plants is 

 far from being complete. We believe that the number oi Closteria is 

 much greater than is supposed by him, and know of many additional 

 species in some of the other genera. 



In the present infancy of our knowledge, much difference of opi- 

 nion may exist as to the characters which should constitute genera ; 

 many may agree with Mr. Hassall in considering Desmidium, for ex- 

 ample, to have been too much dismembered by previous writers ; and 

 some will probably think that he has himself introduced unnecessary 

 divisions, as for example, Arthronema (p. 238) and Hassallia, origi- 



