o J*> 



36 DESMIPS OF THE UNITED STATES. 



reported by Bailey and < Hney, from Florida and from Rhode 

 Island. The measures are taken from Rahenh. Fl. Alg. The 

 figure in Ralfs Br. Desraids, and referred to as belonging to 

 this species is certainly distinct and is a Doddium. 



P. POLYMORPHIC. Pert v. Plato V, tig. 12. 



Sub-cylindrical, smooth, various sizes usually intermingled 

 in larger families ; 34 times longer than broad, ends more or 

 less attenuated, apices rounded ; cytioderm somewhat longitu- 

 dinally striated. 



1 tiameter 1 1-1 5 u. 



Pools, or wet earth, Charlotte, Vermont. Collected by F. 

 Bosford. 



P. Brebissonii, (Menegh), Ralfs. Plate V, figs. 7. 8. 



Cells Bmooth, cylindrical with rounded ends, transverse 

 central band inconspicuous; conjugating cells persistent. 

 1 diameter 1'i IT ". 



Usually cougregated in a mucous stratum in -mall pools 

 ami wet ground.-, Princeton, Ne Jersej Bailey and other 

 localities in the State. The plant mentioned by Wood 

 appears to lit- uearer Cloe&erium obtusum, Breb. 



P. N wi< ri \. Breb. Plate V, fig. l'>. 



Small, broadly fusiform, 15 times longer than broad, 

 tapering from the centre to the rounded apices. Chlorophyl 

 lamina entire ; cytioderm smooth. 



1 diameter 121 7 u. 



Zygospores are -aid to be nearly Bquare, somewhat drawn 

 out between the attached remains of the copulating cells. 

 The plant occurs frequently in trenches ami .-mall ponds of 



Pennsylvania and New Jersey; the fruiting cell-, or zygo- 

 spores have not come under my personal observation. 



I'. JeNNERI, Pa If-. 



Smooth, cylindrical with rounded ends, zygospores orbicular, 



situated between the ( jugating cells which are deciduous. 



I uameter 1 415 fi. 



I have not recognized this form. Bailey reports it from 

 Florida. Rabenhorst describes it a- scarcely distinguishable 

 from P. Brebissonii ; 2^-5 times longer than broad; zygospores 

 mostly globose, membrane somewhat fuscous, sub-granulate. 



