446 PROCEEDINGS OF SOCIETIES. 



scribed. Thus Chloroclados, of Sender, appears to be a good and 

 distinct genus allied to Dasycladus.] 



" The frond iu the Siplionece verticillatoe is simple or dicho- 

 tomous ; it consists of a central tubula unicellular axis, around 

 which are arranged the radiary and verticellate ramuli, the exact 

 arrangement of which yaries according to the genera and to the 

 species. In most of the species carbonate of lime is found 

 deposited in abundance in the outer walls of the main axis and . 

 its ramuli, and this forms around the plant a calcareous enve- 

 lope, in which is reproduced all the details of its organisation. 

 This mineral coating may consist of one or of two calcareous 

 cylinders. The inner cylinder will be formed by the central 

 axis and the first row of cells which arise therefrom. The outer 

 cylinder is laid down by the most external of the yerticels of 

 cells ; these terminate by a splayed-out enlargement, the lateral 

 edges of which become more or less consolidated with the similar 

 enlargements of neighbouring cells, and by thus causing a reci- 

 procal pressure very regular hexagonal surface markings are 

 produced. The organs of fructification are themselves sur- 

 rounded by calcareous material, and assist in the formation of the 

 outer cylinder, a fact easily seen in any section of Cymopolia. 



" The result of such an organisation is that when the organic 

 vegetable matter becomes destroyed there still remains in those 

 fossil species, which laid down a great deal of calcareous material, 

 as well as in those living species, which lay down more or less 

 of it, a skeleton permeated by canals (rays of the ramuli) and 

 chambers (fructification). This arrangement, which permits of 

 an exact classification of the fossil species being wrongly inter- 

 preted, led even some most distinguished authors to see in these 

 morsels of plants the full organisation of a Foraminifer." 



Here it seems desirable to add that the conclusions of the author 

 onthis subject are in every particular acquiesced in by one in every 

 way thoroughly able to judge of the facts. Dr. Ed. Bornet, and 

 on a careful study of the specimens shown, which were prepared 

 by Dr. Bornet, and for which Dr. Wright took this opportunity 

 of thanking him, it was scarcely possible to conceive the demon- 

 stration as admitting of a doubt. 



Mounted specimens of nearly all the recent species were also 

 exhibited. 



Coloured Drawings hy tlie late Mr. Stetoarf, of Edinhitrgh, of 

 some Biqiicolous AJga, exhibited. — Prof essor McNab showed some 

 beautifully executed coloured drawings by the late Mr. Stewart, 

 of Edinburgh, for Mr. Jenner, of that city, of certain rupicolous 

 algas — Glceocapsa sanguinea and others. Amongst these was 

 one of a filamentous form, evidently, on the one hand, related to 

 Scytouema, and on the other, by reason of its tapering filaments, 

 related to Eivularia. A speciality seemed to be that groups of 

 filaments occurred spirally curved and intertwined, giving the 

 aspect of, as it were, a great cable, the scale upon which the 

 drawing was made being large, probably 600 diameters. 



