236 MESSES. ^Y. WEST AND G. 8. WE8T ON 



[WoUe, Desm. U.S. p. 52, pi. 10. figs. 4, 5] in having a basal infl.ation, in having straight 

 sides (not crennlate), in having mnch fewer markings in each ring, and in the rings not 

 extending regularly to the apex. It is very different from F. egregium, nobis \_'=Doci' 

 dkini egregitim, W. B. Turn. Treshw. Alg. of E. India, p. 31, pi. 2. figs. 14, 15], the only 

 other Pleurotcenium of this class. 



Genus Triploceeas, Eail. 

 24. T. GRACiLE, Bail. Micr. Obs. p. 38, t. 1. fig. 10; Nordst. Ereshw. Alg. of New Zeal. 

 & Austr. pp. 64, 65 ; W. B. Turn. Ereshw. Alg. of E. India, pp. 25, 26, t. 2. tigs. 1-4 ; 

 Docidium gracile, Wittr. Anteck. Skand. Desm. p. 21, t. 1. fig. 10. (PI. XIII. 

 figs. 9-13.) Eorma semicelkilis apice trnncatis (vel leviter convexis), ad angulum 

 iinumquemque spina brevi valida extrorsum curvata, lobulis duobus (vel process- 

 ibus) profunde bifidis (interdum trifidis) instructis. 

 Long. 312-422 /u ; lat. ad has. semicell. (c. spin.) 24'5-26-5ju ; lat. apic. 21-25 ^u. 

 Hab. Minnesota. 



All the specimens examined had apices of this character, which are not like the apices 

 of any published forms. 



Genus Closterium, Nitzsch. 



25. C. ABRrPTUM, West, in Journ. Eoy. Micr. Soc. 1892, p. 719, pi. 9. fig. 1. Zygosporse 



globosa}, glabrae. (PL XIII. figs. 14, 15.) 

 Long. 127-135^; lat. 12-5-14'5 jw ; lat. apic. Gin; diam. zygosp. 32-46 ju. 

 Mab. Orono, Maine. 



26. C. Braunii, Eeinsch, Algenfi. Eranken (1867), p. 196, 1. 12. fig. 5; Joshua, in Journ. 

 Bot. xxiii. (1885) p. 35, t. 254. fig. 9 ; Clostermm areolatum, H. C. "Wood, 1874 ; 

 Wolle, Desm. U.S. p. 43, pi. 7. figs. 3,4; O. maculatum, Hastings, in Anier. Monthl. 

 Micr. Journ. xiii. (1892) p. 154, pi. 1. fig. 5. (PL XIII. figs. 16, 17.) 



Long. 622 )u; lat. 43 ^u; lat. apic. 10-11 /<. 



Hah. Scarbro', Maine. 



This has also been observed by Joshua from Nova Scotia, and the figure he gives is 

 more accurate than that of Ileinsch. The plant Ave observed had altogether 10 striae, 

 each composed of an irregular double series of granules, most of which were longitudin- 

 ally elongated. Between the striae the membrane is irregularly punctulate ; the poles 

 are similar to those of C. turgidtmiy but not so much recurved. 



C areolatum, H. C. W^ood, seems to be identical with Beinsch's species. Thus the 

 forma simplicior, Gutw., and forma glabra, Gutw., in Sprawozd. Akad. Krak. xxx. ii- 

 (1895) pp. 36, 37, t. 2. figs. 10, 11), of C. areolatum. Wood, must be regarded as forms 

 of C. Braimii, Beinsch. 



27. C. PR^ELo:NGrM, Breb. ; Babenh. El. Europ. Alg. iii. p. 130. 



Porma brevior, Kordst., Ereshw. Alg. of New Zeal. & Austr. p. 68, pi. 3. figs. 22-24. 

 Long. 230-320 /i; lat. 13-5-16/.. 



