MISCELLANEA. 63 



relative to it, with a view to his making up a notice of the 

 plant for one of our Natural History Journals. I need not, 

 therefore, at this time anticipate his paper by a detail of ob- 

 servations. The interest attaching to it, as possibly one of the 

 last contributions rendered by the classic Car to our science, 

 may excuse me this memorandum. I shall simply append a 

 provisional generic diagnosis framed for it. Probably a closer 

 definition might be drawn; but this seems sufficient to distin- 

 guish it from the allied Paliiiellece. It may, perhaps, be in some 

 degree related to Braun's genus, Schizoclilamys. 



Chlorosphcera. D. Oliv., M.S. Algarum unicellularum genus 

 novum. Cellulce minutcp^ lihercp.^ (jlohosce. Suhstcmtia cellularum 

 interna granulosa (v. vesiculosa?) viridis. Re])roductionis modus 

 incertus. Chlorosphcera. — Species unica. — In aquis turforibus, 

 Frestwick, 1867.— Ibid., May 6, 1858. 



On the Occurrence of a Double Filament in Vaucheria (sp.) (PI. II., 

 Figs. 5 and 6.) — I have by me a portion of a filament of Vaucheria, 

 collected at Prestwick Car in 1856, which presents the singular 

 and very unusual phenomenon of a double cell- wall. This spe- 

 cimen may be about one-third or half an inch in length, the 

 diameter of the outer filament from perhaps l-350th to l-400th 

 inch. Within the outer tube, and continuous nearly through 

 its length, is an enclosed and rather thick-walled cell, containing 

 the altered contents. This would appear to have originated 

 first, by the contents of the outer, older, and parent filament re- 

 tracting from their cell, from some cause unknown, perhaps 

 absence of sufficient moisture; then re-assuming active and for- 

 mative life without regaining their former bulk, forming around 

 them the second, inner filament. The precise cause, however, 

 of this interesting structure it is difficult to indicate. The oc- 

 ciirrence of transverse septa, cutting off portions of contents 

 which may be passing to decay, or about to undergo some of the 

 metamorphoses to which they are subject, in filaments of Vau- 

 cheria, is sufficiently frequent and well known ; but this instance 

 of the longitudinal development of a secondary enclosed filament, 

 to anything like this extent, is, so far as I know, in the Algaa 



