l')0 



THE AMERICAN MONTHLY 



[Juue 



minatioii with a magiiificatiou of two or three hundred 

 diameters. 



I have been able to identify and to mount in Canada 

 balsam, and also dry, the following 58 species of the 

 Diatomaceae in this one gathering, of which over 40 may 

 be seen on a single slide under a g in. circular cover 

 srlass : — 



Pleurosigma atteuuatum 

 " lacustre 



' ' speiicerii 



Nitzschia sigmoidea 

 " parvula 

 " amphioxys 

 Tryblionella angustata 



" gracilis 



Surirella biseriata 

 ' ' ovalis 

 ' ' linearis 

 Pinnularia viridis 

 " viridula 



" oblouga 



" gracilis 



" acuta 



*' radiosa 



Navicula cuspidata 

 •' firnia 



" ampliisbiuiia 



" elliptica 



" gibberula 



" iuflata 



" aflinis 



" cryptocephala 



" biuodis (".•') 



" bleisdiii (?) 



" veiieta (?) 



" producta 



Navicula tumida 

 Stauroueis anceps 

 Cymatopleura solea 



" elliptica 



" apiculata 



Cymbella cuspidata 

 Amphora ovalis 



" niiuutissima 

 Diatom a vulgare 



" elougaturu 

 Odontidium harrisonii 



" mutabile 



" parasitic urn 



Denticula sinuata (?) 

 Gomplionema curvatum 



" coustrictum 



Cyclotella kutziugiaua 

 Coccoueis placentula 

 Syuedra ulua 

 Coccouema lanceolatum 



' ' cistula 



" cymbi forme 



Eucyonema prostratuiii 



" civspitosum 



Achuanthes exilis 

 Eunotia monodou 

 Melosira varians 

 Fragilaria capuciua 

 Colletoneina neglcctum 



This time of year and want of rain were not favorable 

 for Desmids, l)Ut I came across a few vigorous specimens 

 of the following species : — Closterium striolatum (show- 

 ing very clearly tiie })henomena of cyclosis and so-calletl 

 'swarming of the granules' at its extremities), Pediastrum 

 granulatum, Cosmarium botrytis, while among the less 



