90 REVUE BRYOLOGIQUE 



in complete agreement with M^" Cardot on all points^ it 

 seemed well to publish the conclusions at which we have 



arrived. 



The most important of these is to establish the occurence 

 of both H. canariense and //. circinalc in Ireland. This 

 conclusion however is based upon an acceptance of the 

 characters of the two plants as understood 'by Cardot, and 

 it will be well to give a short account of these distinguishing 

 characters, before proceeding any further. 



Limpricht (Laubmoose III, p. 473) repeating my 

 statement as to Moore's Killarney plant being really H. 

 canariense, states that IL circinale is a monoicous plant 

 — H, canariense being undoubtedly dioicous. Cardot 

 however (who has probably had as large a series of H. 

 circinale through his hands as any European bryologist) 

 assures me that Limpricht is in error. The male and female 

 plants are often very closely intermixed, as stated by him 

 in the article above mentioned fRev. Bry. 1. c.) and in 

 Hedwigia, 1893, p, 275 ; but he has never found flowers of 

 both sexes on the same stem. Both H. canariense and 

 H. circinale d^Q^me therefore with H. ciiprcssiforme in the 

 dioicous inflorescence, ditferinginthemnchshortercapsule, 



resembling that of//, mollusciim ; hut in this respect they 

 do not difier markedly, if at all, from one another. The 

 only difference of any importance is to be found in the form 

 and areolation of the leaf base. These characters in //. ca- 

 nariense differ little from //. citpressiforme. The group of 

 somewhat numerous, small, obscure, subquadratealar cells 

 at the angles is not very clearly marked off from the 

 adjacent cells, except in the oldest leaves, where it becomes 

 orange brown; in most of the leaves it is more or less 

 concolorous with the rest of the leaf-base. In //. circinale 

 on the contrary these cells while less numerous are larger, 

 much less obscure, and of an orange brown colour, forming 

 a very small but distinct group on each side at the point 

 of insertion upon the stem. The chief distinction however 

 lies in the for)n of the leaf base; this in H. circinale is 

 widened out immediately above the line of insertion, so as 

 to form shoulders or auricles above the groups of alar cells; 

 above these shoulders the leaf becomes rapidly contracted 

 again, so that the leaf base is decidely hastate in outline. 

 This widening out of the leaf towards its base^ and sudden 

 narrowing again to the line of insertion so as to form 

 rounded auricles, is very marked in a specimen, kindly sent 

 me by Mitten, of the original gathering by Douglas from 

 which the species is figured (Ilook. Muse. Exot.); and is well 

 characterised in all the North American plants I have seen. 

 In H. canariense^ as in //. cnprcssiforme^ on the other 



