79 



My plant has five arms 7 and the membrane is unusually 

 rough; and, in addition, the points on the ends of the arms 

 are very prominent and divergent. 



Staurastrum Helen eanutn, n. sp. St. parvum, 

 granulato-asperura; granulis in series transversas ordinatis; 

 semicellalis subellipticis, dorso modice convexis, ventre tumi- 

 dis; angulis in cornu productis; a vertice triradiatis; radi- 

 orum basis inflatis, marginibus prominentibus apice furcatis 

 vestitia. Diam. .0012 " — .0015". Hab. Splitrock Pond, 

 N. J., frequent. 1880. There is a similarity between this 

 desmid and St. vestitum, Ralfs; but, wbile the latter has 

 two slender forked spines at the middle of each side, nüne 

 has stouter forked processes on the inflated base of each 

 arm; and, in addition to this, the plant is only about half 

 the size of St. vestitum. 



Euastrum attenuatum, n. sp. E. mediocre, diametro. 

 duplo longiore; semicellulis pyramidalibus, basi dilatatis utro- 

 que margine laterali semel sinuatis, in lobum polare rectum 

 truncatum attenuatis; apice crenato-rotundatis; lobo polari 

 uno et lobo basali duobus vel tribus tumoribus instructo; 

 cytiodermate subtillissimo punctato. Diam. et lat. .0013", 

 long. .0026". Hab. Fonds near Bethlehem, Pa. 



Docidium spinulosum, n. sp. D. validum spinu- 

 losum subcylindricum undulatum octies — decies longius quam 

 latius, medio valde constrictum; semicellularum stricturis 

 margine 3-4 plus minus prominentibus, modice attenuatis; 

 cytiodermate dense spinifero; spinulis apicis rotundatis duplo 

 majoribus aliis. Diam. .0016"— .0018". Hab. Fond, Dennis- 



ville, N. J. ; July, 1880. 



Pleurotaenium nodulosum, Breb., Docidium 

 hirsutum, Bailey, and D. nodosum, Bailey, have 

 features in common with this form. I separate it because 

 of the armor of spines with which it is clothed. These are 

 not bairs — not gelatinous contractions, but decided spines, 

 and those of the ends of the cells are longer and stronger 

 than those on the body of the cell. 



Eingegangene neue Literatur und Sammlungen. 



28. Bericht über die IV. Versammlung des westpreuss. Boten.- 



Zool. Vereins zu Elbing 1881. Enthält: Janzen, Die Moos-Flora 

 Elbing's. — Lützow, Bericht über die botan. Untersuchung des 

 Neustädter Kreises. . ,_ 



29. Berkeley and Broome, Nbtices of British Fungi. (*rom 



the Annals and Magazine of Natural History 1882. March.) 



30. Boebm, J. Ueber Schwefelwasserstoffbildung aus Schwetel 



und Wasser. (Sitzb. d. k. Akad. d. Wissensch. 1882.) 



