3°4 



DIATOMS OF SLEAFORD DISTRICT, 1856. 



JOHN LOWE, M.D. 



[In the Proceedings of the Botanical Society of Edinburgh, 1856, 

 p. 13, is a paper by Dr. Lowe on the flora of Sleaford and the 

 Neighbourhood, from which we reprint verbatim the portion 



relating to the Diatomacese]. 



The following Diatomacese collected by Mr. Lowe in the district 

 have been determined by Professor Gregory : — 



Cymbella scotica. 

 Cymbella helvetica. 

 Cymbella cuspidata. 

 Cymbella pisciculus. 

 Cymbella turgida (?). 



Amphora ovalis. 

 Cyclotella operculata. . 

 Cyclotella kutzingiana. 

 Cocconeis placentula. 

 Cocconeis pedicuius. 

 Cocconeis thwaitesii. 

 Tryblionella angustata. 

 Navicula varians W.S. forma (?) 



ovahs-rhomboideus. 

 Navicula elegantula W.G. 

 Navicula bacillum Ehrh. {?). 

 Navicula cryptocephala. 

 Navicula producta. 

 Navicula gibberula. 

 Navicula lepida. 

 Navicula ambigua. 

 Navicula affinis. 

 Navicula sp. (like elegans). 

 Synedra linearis. 

 Synedra radians. 

 Surirelia pinnata. 

 Diatoma vulgare. 

 Diatoma elongatum. 

 Denticula tenuis. 

 Odontidium harrisoni. 

 Odontidium mutabile. 

 Achnanthes exilis. 



Meridion circulare. 

 Achnanthidium lanceolatum. 



Pinnularia oblonga. 

 Pinnularia major. 

 Pinnularia acuta. 

 Stauroneis pheenicenteron. 

 Stauroneis punctata. 

 Stauroneis linearis. 

 Cocconema lanceolatum. 

 Cocconema cymbiforme. 

 Cocconema cistula. 

 Cocconema cornutum. 

 Gomphonema constrictum. 

 Gomphonema tenellum. 

 Gomphonema acuminatum. 

 Gomphonema cristatum. 

 Gomphonema coronatum. 

 Gomphonema capitatum. 

 Gomphonema insigne. 

 Synedra minutissima. 

 Synedra capitata. 

 Pleurosigma attenuatum. 

 Colletonema neglectum. 

 Haemantidium arcus. 

 Fragillaria capucina. 

 Encyonema cxspitosum. 

 Campylodiscus spiralis. 

 Orthosira arenaria. 

 Nitzschia sigmoidea. 

 Cymatopleura solea. 

 Enithemia zebra. 



In remarking upon these gatherings Professor Gregory calls 

 attention to the abundance of Cocconema comutum, which is far 

 from frequent in general, Dr. Gregory having only seen it in two 

 gatherings besides these Sleaford ones; Cymbella pisciculus, also 



and C. turgida, should the form 



He also 



really of this species, of which he has some doubt. 



notices the new forms Navicula lepida, N. elegantula (not yet 



described), and a good many of the 

 Tryblionella angustata, which occurred 

 is also a rare form. 



rm 



Naturalist* 



