NOTES ON LOCAL DIATOMS FOR 1904-1905. 

 By R. H. Philip. 



THE year 1904 was not a very prolific one. The general 

 dry weather tended to restrict the growth, except in 

 perennial springs. 



The most interesting gatherings I took were at Spurn, on 

 the occasion of the visit of the Yorkshire Naturalists' Union. 

 Some washings of Algae, gathered from the foreshore on the 

 Humber side of the peninsula, yielded Actinocyclns Roperii 

 (Breb) Kitt. in abundance. This species was recorded by 

 Norman under its old name Coscinodiscus ovalis, as rare in 

 Ascidian molluscs. It was, however, plentiful enough at 

 Spurn. I also found is same washings Plagiotropis gibberula 

 Grun., and Pleurosigma obscurum W.Sm., and in another 

 gathering from Patrington Haven Achnanthes Danica, 

 Flogel, and Navicida apis. Donk., new records for this 

 district. In fresh water forms, the only new record for the 

 year was Navicula vulpina Kutz. from Hornsea Mere. I 

 have, however, some doubt whether this should be considered 

 a distinct spices, or whether it is merely an unusally large 

 variety of Navicula radiosa. 



Owing to a variety of circumstances, the number of local 

 gatherings made in 1905 has been but few. In the Beverley 

 water supply, two new records have been found in Navicula 

 seminulum Grun. and N. exilissima Grun., both very minute 

 forms. The Pocklington excursion with the Yorkshire 

 Naturalists' Union yielded some interesting gatherings, but 

 nothing new. Melosira arenaria (a very fine and striking 

 form) was plentiful in the Great Givendale springs, along 

 with large quantities of Diatoma hiemale. No other species 

 were found in this gathering besides these two. 



Cleethorpes has again proved a good collecting ground. 

 Stephanopyxis turris, a rare species found by Norman in 

 Ascidian mollucs, has turned up here, also Campylodiscus 

 Thurettii, first found by Mr. F. W. Mills in a slide from the 

 river Humber. Nitzschia socialis Greg., Nitzschia punctata, 

 var. coarctata, and Synedra barbatula Kutz. from the same 

 gathering are now on record for this district for the first 

 time. A recent gathering from shore pools near Marfleet 

 yielded Amphora acutinscula Kutz., A. turgida Greg, and 

 Hantzschia amphioxys var. vivax. This form in the old 



