420 PROCEEDINGS OF SOCIETIES. 



to some of the more common Chsetouotus forms for comparison, for 

 some of the gatherings taken on the same occasion presented 

 Chceionohts larus, Miill. (common), Ch. maximus, Ehr. (rather 

 common), Ch. riracilis, Gosse (rather rare) ; Taphrocampa anmdata 

 (Grosse) also occurred, but this appears to be verv rare, at least 

 quite as rare as Dasydytes. 



Mr. Archer showed (thanks to Prof. Thiselton Dyer) sections 

 made from a sample of tlie "Australian Caochouc," an account of 

 which had just appeared, detailing all that is known of this 

 puzzling substance by Prof. Dyer, in the ' Journal of Botany.' 



IMr. Archer brought down to show the Club a copy of a most 

 valuable memoir from Sweden by P. M. Lundell, for which much 

 esteemed gift he had now most heartily to thank not only the 

 author but also the Hon. N. Jocelyn for so courteously becoming the 

 careful medium of its transmission — this memoir entitled ' De 

 Desmidiaceis, qute in Suecia inventa) sunt, Observationes criticse.' 

 This fine and copious contribution to our knowledge of the 

 Desmidiere, though published in 1871 (so slow is the process of 

 interchange of publications between distant scientific societies) 

 had not before met Mr. Archer's observation, and indeed had 

 only just, through the author's goodness, reached his hands. 

 Here was a great mass of the most careful and extraordinarily 

 exact observations most accurately elucidated. Mr. Archer had 

 from meeting to meeting brought forward several " new " forms 

 obtained from Connemara, and had shown a few drawings of the 

 niost striking, but strange to say here they were or nearly all 

 depicted by Lundell, and not only the very finest of them but 

 several others not less interesting but only less striking, which 

 Mr. Archer had not ventured to take up the time of the meetings 

 by endeavouring to find and exhibit, as, being (some of them) 

 scarce, it would be too large a draught on general patience — 

 several of these too found a place in Lundell' s work. It v/as 

 almost as if that author had made a journey to the same Connemara 

 sites, and found, of course, the same things ! There were still a 

 few (the best, indeed, abstracted !) which as yet have not 

 presented themselves in their most rich localities to the keen 

 eyes of the Scandinavian -workers, but it would take no little time 

 thoroughly to analyse such a large resume of exact observation. 

 It is at least highly satisfactory to find observers to take the 

 pains to examine and Icnoiv the distinctions which hold good 

 amongst these forms, rather than to " cut the gordian knot," as 

 some would do, simply by adoptiug the easier plan of ignoring 

 those difierences which exist, all our discussion thereupon not- 

 withstanding. When he had time to compare his own forms 

 more fully and thoroughly to work up this excellent memoir, 

 perhaps Mr. Archer would have occasion to draw the Club's 

 attention to some points bearing thereon on some future 

 occasion. 



May 22nd, 1872. 

 ■ ■ Dr. J. Barker phowed several of the most "dilficult" diatoms 



