I46 THE FLORA OF HALIFAX. 



the pollution of streams during the last century and a quarter. 

 A few are still gradually, but surely, disappearing. 



It is to be regretted that Bolton, on reaching this portion 

 of his flora, ceased to give his interesting information as to 

 habitat, etc., under each species, as had been done with the 

 flowering plants and ferns in the earlier part of the catalogue. 

 He remarks : " To avoid being tedious, the places where the 

 mosses and lichens in Halifax parish are to be found will be 

 omitted, and their species only enumerated by their trivial 

 names, as mentioned in Hudson's Flora Anglica ; but the more 

 curious Botanic Reader, by application to the Publisher, may 

 be informed where he may receive ample information concern- 

 ing any or all of these." We should have preferred him being 

 " tedious." He would have preserved to us much valuable 

 information concerning the surroundings of Halifax and the 

 district generally, as they appeared at the time he sought out 

 their botanical treasures. 



The next source of information in order of date is the 

 herbarium of Roberts Leyland. It contains about no species 

 of mosses, collected within the parish, and many more from the 

 doughs just over the borders on the Lancashire side. The 

 majority of the packets are dated 1834 and 1835. One speci- 

 men, Ovthotricum crispum, was collected on trees in Ogden 

 Clough, November 14th, 1819, and is still in very good exam- 

 inable condition. Many packets afford evidence that both 

 Gibson and Nowell communicated mosses to this herbarium. 

 It is now at Belle Vue, and the mosses are stored in a series of 

 card-board boxes, each with a printed index of its contents. 

 I am sorry to say the last of the series is missing : this is to be 

 regretted, seeing that several interesting Hypnums come at the 

 end. 



There is another collection of mosses at the same place, 

 presented by Colonel Akroyd, but being mostly from other 

 districts, these do not afford much local information. 



Nowell's portfolio of British mosses, now in the safe custody 

 of the librarian at the Free Public Library, Todmorden, has 

 been examined. It is in a good state of preservation, and 

 contains, amongst others, 147 species collected within a few 

 miles of Todmorden. The only drawback connected with this 

 collection, is, that in many instances, the exact station and 

 date when and where the moss was found are not given. In 

 such cases " Near Todmorden " may mean either the Lanca- 

 shire or the Yorkshire side of the boundary. This omission 



