W. WEST AND G. S. WEST: ALGA-FLORA OF YORKSHIRE. 9 



the most important of which are: — Additions to the Algae of 

 West Yorkshire, Nat., March and April, 1889; Algae from 

 Birkdale Tarn, Nat., Aug., 1889; Freshwater Algae of North 

 Yorkshire, J. of Bot., vol. 27, 1889; Additions to the Fresh- 

 water Algje of West Yorkshire, Nat, Aug., 1891 ; Notes on the 

 Freshwater Algae of the East Riding of Yorkshire, Nat., July, 

 1893. There are also three papers of importance by W. B. 

 Turner; these were published prior to the 'Flora of West York- 

 shire,' and are: — The Algae of Strensall Common, Nat, Dec, 

 1883; Notes on Freshwater Algae with descriptions of new 

 species, Nat, Feb., 1886; Notes on Algse collected at Gormire 

 and Thirkleby, Nat, Sept, 1887. In addition to the above 

 there is a paper which was published by George Norman in i860, 

 entitled 'List of Diatomaceae occurring in the neighbourhood of 

 Hull,' Trans. Micr. Soc, vol. 8. Since the appearance of the 

 above papers a large amount of material has been collected and 

 examined from many parts of the county, with the result that the 

 number of species has been greatly increased, and a large 

 number of additional localities have been found for species 

 already recorded. 



The authorities in brackets after some of the localities refer 

 to the persons who have recorded the species from those localities, 

 and if the mark ! follows the locality we have also seen a 

 specimen from that locality. In all other cases the records are 

 entirely our own. 



We here express our indebtedness to all who have at any 

 time collected material for us, our thanks being especially due 

 to Mr. LI. J. Cocks for some most excellent gatherings from 

 Pilmoor, as well as various material from Harrogate, Knares- 

 borough, near Jervaulx Abbey and other places. Mr. J. 

 Beanland collected for us in certain parts of the East Riding, 

 Mr. I. H. Burkill in the Scarborough district, Mr. W. Denison 

 Roebuck in Upper Swaledale, from Birkdale Tarn, etc., the Rev. 

 W. Fowler about Liversedge, etc., and Mr. J. J. Marshall about 

 Market Weighton. Mr. M. H. Stiles sent us some slides of 



