2 14 Philip : The Finding of a Fdvioits East Yorks. Diatom. 



hand, in what mig-ht be termed a hygrophilous form, the whole 

 thallus is broader and thinner, the reduction in thickness chiefly 

 affecting the compact tissue of the midrib ; the cells of the 

 epidermis have thinner walls and contain numerous chloroplasts ; 

 the pores are wider ; the rhizoids are fewer, and the peg-like 

 ingrowths of the tuberculate kind are shorter ; and the cell- 

 walls in the ventral scales are colourless or only slightly tinged 

 with purple. 



THE FINDING OF 

 A FAMOUS EAST YORKSHIRE DIATOM. 



R. H. PHILIP, 

 Hull. 



In view of the great number of works on the Diatomaceae now 

 existing, one scarceh^ realises how recent ihe study really is. 

 The earliest book which Van Heurck in his bibliography of the 

 subject considers worth mention is Agardh's ' Conspectus 

 Criticus Diatomacearum,' published in 1830; and until the 

 appearance of Rev. Wm. Smith's ' Synopsis of the British 

 Diatomaceae,' in 1853-56, the only works in English were casual 

 references in books devoted to the xAlgcE generally, such as those 

 of Hassall and Greville, and still more casual papers in the 

 microscopical journals. 



But in the fifties a strong interest in this subject set in, and 

 among many ardent workers a little group of Hull naturalists 

 gained a prominent place. The names of Norman, Harrison, 

 SoUitt, and Munro are well known to all Diatom students. 

 Norman's patronymic has been immortalised in the specific 

 titles of several species, but these are either exotic or fossil 

 forms. Sollitt has given his name to Anlacodiscus Sollittianus, 

 but this was also a foreigner, until the writer, a few years ago, 

 found it living" in the river Hull. The name of Harrison is, 

 however, appended to one of special interest to us, as it was 

 found first in our neighbourhood, and figured and described 

 from our local work. Fragilaria — or, as it was first named, 

 Odontidium Harrisonii , is stated by Van Heurck to be very 

 rare, and though occasional frustules may have been found in 

 many places, I am not aware that there is any locality where it 

 can be found so certainly and so abundantly as in the Haltem- 

 price springs, about three miles from the Hull City boundary. 



Naturalist, 



