1863.] PONDWEEBS. 461 



The 7tli, P. ramosum angustifolium, has no name bearing the 

 honours of its paternity. It was communicated by Dr. Frank, 

 and is described in Bauhin^s ' Prodroraus.'' 



The remaining species or forms named in the ' Pinax/ and 

 described in the ' Prodromus/ may be considered as unknown 

 or doubtful ; no author has identified them with recognized spe- 

 cies of the present day, 



Gerard and Parkinson did not contribute much to the know- 

 ledge of our British Potamacece. 



One of our earliest botanical catalogues, viz. that of the Ox- 

 ford Garden, 1651, contains five or six species ; one being, as 

 might be suspected, Polygonum amphibium. These are P. natans, 

 P. lucens, P. perfoliatus, and P. pectinatus {ferulae, folio) or 

 some other joined with it (P. gramineum ramosum), P. grami- 

 neus, Sm.? 



In Ray's catalogue of the plants of England {' Catalogus Plan- 

 tarum Anglise') there are nine species, but only six when the 

 Polygonum, Ruppia, and Zannichellia are deducted, for these aU 

 figure as Potamogetons in all the works of this period. In his 

 * Synopsis of the British Plants,' 1696, there are ten species with 

 Ruppia. The increase is among the grass-leaved species. One 

 of these is P. compressus, another P. pusillus. 



In Dillenius's edition of the 'Synopsis' there are sixteen species 

 described or named, and of these, six are generally supposed to 

 be well-known species of the broad-leaved kinds, viz. P. natans, 

 P. lucens, P. perfoliatus, P. crispus, P. serratus, Iluds., P. 

 densus, Dillenius's No. S"^. P. rotundifolius, Loesel, p. 205, 

 and which Haller, No. 844, calls a distinct species, may possibly 

 turn up in British waters. 



The narrow-leaved species of Potamogetons in the 'Synopsis' 

 are not determined, possibly not determinable. 



In Hudson's 'Flora Anglica,' 1st ed. 1762, there are ten spe- 

 cies described, viz. five broad-leaved species as above, omitting 

 P. densus, which he appears to unite with P. serratus. He has 

 an equal number of narrow-leaved forms, viz. P. compressus, P. 

 gramineus, P. pusillus, P. pectinatus, and P. marinus. Withering, 

 in his 3rd ed. 1796, added one species to the above, P. seta- 

 ceus, and this eminent author also throws some doubt on Dille- 

 nius's figure of P. gramineus, p. 150 of the ' Synopsis,' quoted by 

 Linnaeus, Haller, Hudson, etc., and which has always been re- 



