332 NOTES ON FRESHWATER ALGM. 



tively wider ends, and has more turns of the chromatophore. It 

 differs from S. fnsiformis in its larger size, its more rounded poles, 

 and in having more turns of the chromatophore. 



8. Mesotsenium purpureum, sp. n. M. cellulis libere na- 

 tantibus, cylindricis et leviter curvatis, polls rotundatis, diametro 

 3|^-4|^-plo longioribus ; chromatophoris in medio cellularum non 

 interruptis, purpureis. Long. 32-46 /x; lat. 9*5-10 /x. 



Hab. Peat bogs, Old Cote Moor, W. Yorkshire. 

 The protoplasm was full of granules of various sizes, in addition 

 to the pyrenoids, the latter being scattered. 



9. Penium cuticulare West & G. S. West in Journ. Roy. Micr. 

 Soc. 1896, 153, t. iv. f. 43, 44. Prof. Schmidle states {Nuova 

 Notarisia, 1897, 69) that this species is identical with P. cylindrus 

 Breb. var. siibtiimcatiun Schmidle, var. coloratnm Schmidle, Oesterr. 

 botau. Zeitschr. t. xiv. f. 27, 28. This may be so, but at the same 

 time we may state that it is not a variety of P. cylindrus. He also 

 states that it is near P. Lewisii W. B. Turner, but P. Lewisii = P. 

 exigmun West, forma Lewisii ; and although P. cuticidare is near 

 P. exiguum, we yet think that these two species are sufficiently 

 distinct, P. cuticidare differing from P. exiguum in being somewhat 

 larger, in never being constricted in the middle, in never having 

 dilated apices, as well as in its red-brown cell-membrane. 



10. Closterium pseudospirot^nium Lemmermann, var. variabile 

 Lemmermann, Zur Algenfl. des Riesengebirges, Forschungsberichte 

 aus der Biol. Stat. Plun, iv. Theii, 1896, 119, cum fig. 12-14. This 

 presents many resemblances to forms of lihaphidium, being almost 

 identical with B. polgmorphum var, 7nirahile West & G. S. West, 

 Journ. Roy. Micr. Soc. 1897, 501, pi. vii. f. 9-13. Lemmermann 

 does not state whether or not there is an apical locellus with moving 

 corpuscles in his species. This, if regularly present, is a diagnostic 

 feature of Closterium, yet R. polymorphum var. mirabile sometimes 

 possesses a solitary moving corpuscle. 



11. Closterium coloratum (Klebs) Gutw. Rosprawy Akad. 

 Umiej. Krakow. Wydzial. mat.-przyr. xxxiii. 38, t. v. f. 16, t. 6, 

 f. 16 (1896). This species seems to differ very little, if any, from 



C. lunula var. intermedium Gutw. (I.e. t. vi. f. 17), and should be 

 regarded merely as a variety (v. coloratum Klebs) of C. lunula. 



12. Closterium Cordanum Gutw. I. c. 40, t. vi. f. 19. This 

 seems to us but a form of C. Malinvernianum De Not with rather 

 thicker apices. 



13. Closterium galiciense Gutw. I.e. 39, t. vi. f. 18. We con- 

 sider this also to be but a form of C. moniliferum, (Bory) Ehrenb. 

 with thicker apices. 



14. Pleurot^nium annulatum (Josh.). Docidium an7iulatum 

 Josh, in Journ. Linn. Soc. bot. xxi. 651, t. xxv. f. 13 (1886). 



D. egregium W. B. Turner in K. Sv. Vet.-Akad. Handl. Bd. 25, 

 no. 5, 34, t. ii. f. 14, 15 (1893). Having recently examined some 

 of the original specimens of D. annulatum Josh., we were surprised 



