191 7- M'Ardle. — Bryophyta of Glen of the Downs. 77 



In our work of collecting we noted with interest the 

 number of genera which grow together for their mutual 

 support ; from one patch on the table of a dissecting micro- 

 scope we found Frullania Tamarisci, Lophocolea cuspidata, 

 Lepidozia reptans, Scapania nemorosa, S. gracilis, Diplo- 

 phylliim albicans, Ccphalozia lumdaefolia, C. hiciispidata 

 and a moss, Mnitim pimctatum. These were with difficulty 

 separated, so closely were they interwoven. The curious 

 cucullate or saccate lobules on the leaves of Frullania 

 Tamarisci were unusually large and well developed in rock 

 specimens in this glen. They hold water, and it is remark- 

 able that in places where there is constant moisture, or 

 water tricjding over the place where the plant grows, these 

 water-holders become smaller ; when constantly sub- 

 merged they become almost rudimentary. 



We found several specimens showing the asexual mode of 



reproduction by budding which is more frequently seen 



than in the mosses ; the subject has been fully discussed 



from my own observations in Irish Naturalist, Vol. IV., 



'p. 81, pi. 3, 1895. 



My best thanks are due to Mr. H. N. Dixon of 

 Northampton, whom I consulted in matters of doubt 

 relating to mosses. These lists would not be so extensive 

 were it not for the help rendered by Mr. W. F. Gunn, of 

 Dublin. 



MUSCI. 



Tetraphis pellucida Hedwig. — Plentiful in fruit on turfy banks and on 

 decayed wood up to 700 feet. Dissected capsules show the possible 

 origin of the peristome, composed of four solid conical teeth, derived 

 from the fission of the whole cellular tissue of the interior of the 

 operculum or lid ; they mark a very primitive stage in that organ, 

 so highly developed in other mosses. Plate I., Fig. i., shows a micro- 

 photograph of the protonema with the frondiform leaves which appear 

 on the first development of the moss stem. They are ovate-spathu- 

 late from a narrow base ; at first they are often ligulate ; they 

 disappear before the development of the moss stem is completed, and 

 are rarely seen for this reason. 



Catharlnea undulata Web. & Mohr. — On shady clay banks up to 700 

 feet ; not common. 



