REVUE BRYOLOGTQUE 23 



characters, are quite consistont with anotlier hypothesis which 

 naturally presents itself in the case of a plant holding an interme- 

 diate stage between two closely allied species, viz. that of hybri- 

 dity. In support of this hypothesis there is also the somewhat 

 cogent argument that the distribution of R. iilorcum coincides, 

 broadly speaking at least, with the region where It. lenellum and 

 li, curvisehtra occur intermixed , namely the Mediterranean 

 region ; w^hile in Britain, the only district so far as I am aware, 

 outside the Mediterranean region, in which it has been found, 

 R. lUoreum has so far been delected only in the South of England, 

 where both the suggested parents are known to occur. 

 Northampton (England), East Park Parade 23. 



H. N. Dixon. 



Note on Tortula rigida Schrad. and Tortula brevirostris 



B. and Grev, 



An attempt to find the rare T. brcviroslns, formerly recorded 

 for the neiglibourhood of Buxton^ lias led to a result to which it 

 may be desirable to direct attention. The only plants met with 

 appear referable to T. rirjida, showing however a considerable 

 ' amount of variation in the size number and direction of the leaves, 

 and in the lengths of the capsules and lids. An examination of the 

 inflorescence however has given an unexpected result. None of 

 the plants with sho7^t lids were synoicous, while on the other 

 hand out of about -10 plants G, which in other respects agreed 

 with T. rigida, proved to be synoicous. None of the plants seem 

 to be true 7'. brevirostris .hul a certain percentage of them possess 

 one or more of the characters, including synoicous inOorescence, 

 which are commonly supposed to distinguish that species. 



Mr H. N. Dixon informs me that he possesses two specimens 

 from the same locality, one of which is normal 7'. rigida, but the 

 other agrees very closely with J . brevirostris, except that the 

 inflorescence is not synoicous. Bryologists, who have access to 

 abundant specimens, by ascertaining if similar variations occur in 

 other localities, may help to confirm or remove a doubt as to 

 whether T. rigida and T. brevirostris are really distinct species. 



Buxton, England. 



T. Barker. 



V 



