ALGOLOGICAL NOTES 87 



that Mr. Playfair's description and figure (as far as they go, and 

 they are very imperfect) of " Closterium naviculoideiim " not only 

 agree very well with Nitzschia acicularis, but that author actually 

 states that there was some doubt in his mind as to whether the 

 plant was not the Diatom Nitzschia acicularis Smith. Under such 

 circumstances Mr. Playfair had no reason for foisting another 

 synonym upon an already overburdened nomenclature. 



As regards Ankistrodesmns nitzschioides, I may say, first, 

 that I am not " quite unconscious" of any Alga I have described ; 

 and, secondly, that my remarks under the diagnosis of the species 

 clearly show that I had carefully considered its resemblance to 

 the attenuated species of Nitzschia, all of which I know quite 

 well. The attenuated spine-like apices of this Alga, like those of 

 A. S])irot<2nia and others, are of quite a different nature from the 

 attenuated frustules of any species of Nitzschia, and, moreover, 

 the cells are isodiametric. It might also be mentioned that 

 " chromatophora pallide viridi, pyrenoidibus nullis " is a statement 

 of fact. 



8. Ankisteodesmus falcatus (Corda) Ealfs var. acicularis 

 (A. Br.) G. S. West. Some very long forms of this variety occurred 

 abundantly in the reservoir at Barnt Green, Worcestershire, in 

 May, 1910. Long. cell. 146-165 /x ; lat. 3-3-4 fx. (Fig. 3, C.) 



9. Actinasteum Hantzschii Lagerh. in Ofvers. af K. Vet. 

 Akad. Forhandl. 1882, n. 2, p. 70, t. 3, f. 25-26 ; Schroder in Ber. 

 Deutsch. botan. Ges. xv. 1897, t. 25, f. 3. This rare Alga has few 

 British records. It occurred in small numbers in the surface- 

 waters of the canal at Lifford, Worcestershire, in October, 1910. 

 Long. cell. 16-21 jx ; lat. cell. 3-3-5 fx. It is known from the 

 plankton of the Kiver Thames. 



10. Hydeueus fcetidus (Vill.) Kirchn. This member of the 

 SyngeneticcB was collected in the swiftly running Eiver Plym at 

 Shaugh Bridge, in Devonshire, in April, 1910. The collectors 

 were Miss Olive E. Hood and Mr. K. H. Whitehouse, who informed 

 me that the current was very strong and the water very cold, due 

 to melting snows on the moorlands from which the river flows. 

 It is an interesting record for one of the southern counties, wliere 

 one would scarcely expect to find such a denizen of alpine regions. 

 In the British Islands it has been previously recorded from Scot- 

 land and North Yorkshire. 



11. Synedea actinasteoides Lemm. in Ber. Deutsch. botan. 

 Ges. 1900, xviii. p. 30. This interesting Diatom occurred in 

 some tow-nettings made in the canal near Lift'ord, in Worcester- 

 sliire, in October, 1910. It has not previously been recorded for 

 the British Islands. It belongs to that section of the genus 

 Synedra named by Lemmermann " Belonastnun," in which the 

 cells are associated to form free-floating colonies, each colony 

 consisting of a cluster of Diatoms radiating from a centiul point. 

 Long. valv. 54-59 /x ; lat. 2'6-3 /x. About 8 cells were present in 

 each colony, but the number, although variable, was well within 

 the limits given by Lemmermann of 4-16. The dimensions were 



