148 MOSSES WITH A HAND-LENS 



sometimes a foot or more long. The Giant Water Moss rarely 

 fruits. 



FoNTiNAUS DALECARLiCA B. & S., the Common Water Moss, 

 is everywhere abundant and usually fruits freely, the capsules 

 maturing in summer. As will be seen from the plate, the cap- 

 sules are almost entirely covered by the perichsetium and are 

 borne on the older portions of the plant from which the leaves 

 have fallen. One must not be too sure that he has found this 

 species until he has studied it with a compound microscope, as 

 there are several other common species that are not readily 

 distinguished from it. 



This last statement has particular force from the fact that the 

 branch figured in b, plate XXXIX, is not P. dalecarlica as was 

 stated in the First Edition, but 



F. NovaE-AngliaE Sulliv., which was collected from the same 

 brook and almost intermingled with P. dalecarlica which was 

 figured natural size in the same plate. The figure of a branch of 

 P. dalecarlica from the Bryologia Europea will enable one to dis- 

 tinguish the two species in most cases. 



Plate XXXIX. a, Pontinalis dalecarlica X Vz^ b, Branch X 5 of F. 

 Novae-angliae. c, Portion of plant bearing capsules X 5- d, A short 

 branch of F. gigantea. 



