652 ME. W. JOSHUA ON BUBMESE DESMIDIEJE. 



15. Clostebium, Nitzsch. 



C. DiAN-E, Bhrenb. 



C. costatum, Corda. 



C. Ensis, Delponte. 



C. Bacillum, n. sp. (Plate XXII. figs. 4, 5, & 6.) 



C. robustum, fere rectum, diametro 6-10-plo longius, cylindri- 

 cum: apicibus plus minus attenuatis, conos obtusos sisteutibus : 

 membrano crasso, laevi, in adulto pulchre pallido-ochraceo : lineis 

 mediis 2-3 apud punctum junctionis. Longit. 200-235 /i, latit. 

 24-35 /i. 



Stout, nearly straight ; 6-10 times longer than wide, cylin- 

 drical ; apices more or less attenuated, forming obtuse cones ; 

 membrane thick, smooth, in maturity of a fine delicate ochre ; 2 

 or 3 median lines at point of juncture. Nearest to C. didymotocum, 

 Corda, and C. antiacerosum, De Notaris. Length 200-235 /* ; 

 width 24-35 p. 



C. lagoense, Nordst. 



C. steiolattjm, Bhrenb. 



C. lineatum, Bhrenb., f. sandvjcensis, Nordst. 



C. Ea.lfsii, Breb. 



C. acekosum, Schrank. 



C. setaceum, Bhrenb. 



C. junctdum, Balfs. 



C. VENUS, Kutz. 



C. INTEBMEDIUM, Balfs. 



C. iffcUBVUAT, Breb. 



C. acdtum, Breb. 



C. Lejbleinii, Kutz. 



C. pobbectum, Nordst. 



C. subtile, Breb. Conjugated with quadrate zygospores. 



C. nematodes, n. sp. (Plate XXII. figs. 7, 8, & 9.) 



C. lanceolatum, diametro 10-11-plo longius, sensim curvatum, 

 ceutro haud inflatum, striis tribus transversis, apicibus paulo 

 utrinque dilatatis, inflationem prominentem ovatam ferentibus, 

 ultra abrupte attenuatis: membrano crasso, flavido-fusco, lon- 

 giludinaliter striato, striis 18-20. Longit. 187 /l*, latit. 20 [*, 

 latit. ad inflationem 13 /u. 



Lanceolate ; 10-11 times longer than wide, gradually curved, 



