304 Clark : 



Wash 



large underleaves in / Allenii are by no means frequent, many 

 stems failing to show them altogether, yet they constitute a strik- 

 ing feature of the species. 



JUNGERMANNIA RIPARIA TayL 



1843. 



1874. 



Jnngermannia riparia Tayl. Ann. &Mag. Na 

 Aplozia riparia Dumort. Hep. Europ. 63. 



On rocks. Foothills of Mount Ranier, Alleji. New to the 

 United States but widely distributed in Europe and already re- 

 ported from British Columbia. 



The closest allies of/, riparia are /. cordifolia^ J. atrovirens 

 Schleich., and/, pumila With, In some respects it is intermediate 

 between the first two and agrees with them in its dioicous inflores- 



cence. 



/• 



more prostrate habit, producing an abundance of rhizoids and 

 flagella. Its leaf-cells are also distinct in developing trigones, 

 those of / cordifolia having walls of uniform thickness. When 

 compared with / atrovirens^ / riparia is seen to be considerably 

 larger and less deeply pigmented, but the two species are appa- 

 rently connected by intermediate forms. / piiuiila can be at once 

 distinguished by its paroicous inflorescence. 



1879. 



1882. 



Hygrobiella LAxiFOLiA (Hook.) Spruce 



Jungennannia laxtfoUa Hook. Brit. Jung. //. 5^. 18 16. 

 Gymnocolea laxifolia Dumort. Recueil d'Obs, Jung. 17. 1835. 

 Cephalozia laxifolia Lindb. Muse. Scand. 3. 

 Hygrobiella laxifolia Spruce, On Cephalozia ; _ 

 Cephalozia Notarisiana Massal Accad. Sc. Med. Nat. Ferrara 201. 

 1903. 



On wet rocks. Paradise Valley, Mount Ranier, Frye. New 

 to the United States, but widely distributed in Europe and already 

 reported in North America from Greenland and Labrador. 



Although a small species, H. laxifolia exhibits a number of 

 very distinct features. The plants grow in tufts, and the ascend- 

 ing or erect stems develop few or no rhizoids. The branching is 

 lateral, some of the branches being similar to the stem and some 

 flagelliform. The transversely inserted leaves are distinctly com- 

 plicate and equally bifid for about one third their length with acute 



