282 MESSRS. W. WEST AND G. S. WEST ON 
12. Pentum Drarrvs, Bréb. in Ralfs, Brit. Desm. p. 150, t. 25. 
f. 3. Closterium Digitus, Ehrenb. ; C. lamellosum, Bréb.; Penium 
lamellosum, Kütz.; P. navigium, W. B. Turn. in K. Sv. Vet.- 
Akad. Handl. xxv. no. 5, p. 17, t. i. f. 9. 
Johnson found this species abundant from many States. He 
remarks, “J fear I have not learned to distinguish P. Digitus 
from P. lamellosum.” | Cfr. West & G. S. West in Journ. Bet. 
xxxiii. Mar. 1895, p. 66. 
13. P. MARGARITACEUM, Bréb. in Rafls, Brit. Desm. p. 149, 
t. 25. f. 1a-c. 
Noticed from many States; Jat. 22-32 u. The specimens from 
Plymouth, N.H. (H. J. no. 353), are worthy of mention as they 
did not show the linear arrangement of the markings. 
14. P. SPIROSTRIOLATUM, Barker, in Quart. Jour. Micr. Soc. 
N. S. ix. p. 194. 
Long. 148-220 p; lat. 16-19 p. 
Hab. De Land, Florida, not rare; also Tallahassee, Florida. 
15. P. w1xvuTCM, Cleve, in Ofv. K. Vet.-Akad. Förh., Arg. xx. 
1863, no. 10, p. 493.—Docidium minutum, Ralfs, Brit. Desm. 
p. 158, t. 26. f. 5. 
Var. czassuM, West, in Journ. Linn. Soc. (Bot.) xxix. p. 130, 
t. 20. f. 1. 
The specimens were all rather more attenuate than any we 
have previously seen, and had a punctate cell-membrane. Long. 
46-70 u; lat. 12-19 p. 
Hab. Florida (H. J. no. 545). 
VI. ROYA, West & G. S. West. 
16. R. optusa, West & G. S. West, in Journ. Roy. Micr. Soc. 
1896, p. 152.—Closterium obtusum, Bréb. in Mém. Soc. Sci. Nat. 
Cherbourg, iv. p. 154, t. 2. f. 46. 
Lat. 7 p. 
Hab. Glencoe, Ill, 1890. Single specimen found (H. 4. 
no. 85). 
VII. CLOSTERIUM, Nitzsch. 
17. C. xuNvVrA, Nitzsch; Ralfs, Brit. Desm. p. 163, t 27. f. 1. 
Hab. Near Tallahassee, Florida, scarce. “In some speci- 
mens a wide colourless sheath covered with dirt &c. was seen.’ 
