3-6 



INTERESTING DIATOM NEAR HULL. 



R. H. PHILIP. 



In the ' List of Diatomaceiie occurring in the neighbourhood of 

 Hull.' published in 1S59 George Norman, appears the follow- 

 ing record: — ' AmpJiiprora constricta Ehr. Very common 

 in brackish water. Pure near Marfleet. Victoria Dock Timber 

 Pond, Marsh Chapel, Garrison Moat, Dairycoates, under 

 Railway Arch.' 



I had frequently sought for this form in the neighbourhood 

 of Marfleet, but without success until early in May this year, 

 when, on the occasion of a visit of the Hull Scientific Club 

 to the excavation now going on for the new dock, I found it 

 in great abundance and pure of any mixture with other 

 species, in water oozing from the face of cuttings and forming 

 pools at the bottom of the excavation. 



This diatom has given a great deal of trouble to the author- 

 ities by its anomalous structure, and by three leading diatomists 

 it has been assigned to three distinct genera. Ehrenberg gave 

 it the name of Amphiprora constricta, under which it appears 

 in Norman's list. Donkin, who found it on the Northumberland 

 coast, called it Navicula simulans, and Grunow describes it as 

 Stauroneis amphoroides. 



When Mr. F. W. Mills and myself were revising Norman's 

 list, it seemed to us that the last of these names was the most 

 appropriately descriptive, so it appears in the illustrated 



Naturalist^ 



