393 



Marin and San Mateo counties, California,* but a scrap of it had 

 been previously collected (1888) with PolytricJnun by Miss M. E. 

 Parsons, of San Rafael, and overlooked in my collection. It is 

 found mostly on the ground and is an interesting addition to our 

 flora. It has long been known in Europe, but does not appear to 

 be common. It was distributed in Hep. Am. 174, from fine ma- 

 terial sent by Mr. Howe. The species has been illustrated in Smith, 

 Engl. Bot. //. 2^10 and in Ekart, Syn. Jung. Germ.//. g,f. 6g in 

 addition to the citation of Hooker above. 



Species dubiae et Itiqulrendae. 



Cephalozia dentata (Raddi) Spruce, On Cephalozia, 71. 1882. 



Jimgermannia dentata Raddi, Mem. Soc. Mod 18 : 22. pi. 4. J. 4. 

 1818. 



(This species was reported by Mitten, Jour. Linn. Soc. 8:52, 

 1865, under the name Trigona7tt]iiis dentatus, from Galton Moun- 

 tains, British Columbia, but as it is not otherwise known from 

 North America the identification needs to be verified.) 



Cephalozia connivens (Dicks.) Dumort, Recueil d' Obs. sur les 



Jung. 18. 1835. 



Jiingerniannia connivens Dicks. PI. Crypt, Brit. fasc. 4: i^. pi. 

 II. f. 75-. 1 80 1. 



CcpJialoziamidtiflora Lindb. Acta Soc. Sci. Fenn. 10 : 501. 1875. 

 (not Spruce /. c.) 



(This species has been frequently reported from America but 

 has been confused with C. media. It is likely to occur northward 

 and can be distinguished from that species by its large leaf-cells 

 (66 ,a in diameter) and its perianth formed of a single layer of cells, 

 with long ciliate mouth.) 



* * 

 The publication of a revision like the above is often accepted 

 by botanical collectors as an indication that the information re- 

 garding the genus is closed. As a fact such a revision merely in- 

 dicates the extent of our knowledge for the present and forms a 

 datum line for further study. It also shows or ought to show the 

 limitations of our knowledge. The remarks to follow apply not 

 only to the genus Cephalozia, but to all genera and species of He- 



*Erythea, 4: 50. 1896. 



