1158 



course tlie incorrect figure is omitted in my third edition ; and so it 

 will hereafter stand as Mr. Moore's own. 



In instances, Mr, Moore has ventured to differ from me ; but, 

 whenever this is the case, he is obscure in his explanations. Thus, 

 on the " dilatata group " he asserts, at p. 118, that uliginosa is exactly 

 intermediate between cristata and spiuulosa, and, at p. 131, that 

 glandulosa is quite intermediate between dilatata and spiuulosa ; yet 

 he asserts that cristata, uliginosa, and spinulosa constitute one spe- 

 cies, and dilatata, uliginosa, &c., another; and, at p. 114, he says 

 these two species are readily distinguished. This is as if a man 

 should say that A and B are readily distinyuished from C and D, 

 but that D is qiiite intermediate between B and C. Like confusion 

 occurs in the Woodsias, &c. 



I cannot object to this book as doing me an injury ; I think it will 

 rather excite a thirst for that more correct knowledge which, for six- 

 teen years, 1 have been anxiously endeavouring to acquire, and which, 

 from time to time, I shall do my best to make public. 



Edward Newman. 



On Potamogeton Jlahellal us, Bab. 

 By Charles C. Babington, M.A., F.L.S.* 



In the second edition of the ' Manual of British Botany,' I intro- 

 duced a note to the effect that a Potamogeton inhabiting the canal 

 near Bath would probably prove to be a new species, belonging to 

 the group of which P. pectinatus is the type. It is there stated that 

 " its dry fruit is semi-obovate compressed with 3 (?) obscure keels on 

 the back ;" and that its leaves have " transverse veins." The plant 

 thus noticed was gathered by myself, so long ago as the year 1830 ; 

 since which time I have scarcely ever visited Bath during the summer, 

 and have thus had no opportunity of examining it in a living state. 



In the interval between the publication of the second and third 

 editions of the ' Manual,' I persuaded myself that the plant might 

 safely be referred to R. pectinatus (still judging only from dried spe- 

 cimens in the flowering state), and therefore, in edition three, erased 

 the remark that had previously appeared. 



* Read at a meeting; of the Linnean Society, Nov. 15, 1853 ; and comrauuicated 

 by the authof. 



