Fresh-water Algfe, &c. Bij A. W. Bennett. 15 



Mesocarpe^. 



Mesocarpiis scalaris dBy. 



Mesocaepus (?) NEAUMENsia n. sp. Figs. 31, 32. 



Sterile cells 125 yu, long by 20 to 25 /a broad. Endochrome in 

 a single axile plate, with one row of large starcb-corpuscles, and 

 numerous smaller ones. Conjugation lateral, between two adjacent 

 cells. Fertile cells somewhat ventricose, 200 fju long by 50 fi 

 broad at the widest part, connected with the adjoining empty cell 

 by an elbow 50 jju broad, across which the dividing septum reaches 

 only about half-way. Zygosperm oval, 90 /x by 40 fx, always 

 nearer to the end of the cell where conjugation has taken place ; 

 cell-wall of zygosperm quite smooth. 



Gathered in a duck-pond, Neaum Crag, Skelwith Bridge. I 

 am doubtful about placing this interesting species under Mesocarpiis. 

 It agrees with that genus altogether in general appearance and in 

 the arrangement of the endochrome ; but I am quite unable to 

 detect the extra membrane to the zygosperm on which de Bary 

 and Wittrock rely to establish the essential difference in the process 

 of " spore-formation " in the Mesocarpeae and Zygnemeae ; and 

 wherever lateral conjugation has been observed in Mesocarpus (by 

 de Bary), the zygosperm is formed not in one of the two cells, but 

 in the connecting canal between them. In some respects, especially 

 the ventricose appearance of the fertile cells, it approaches Wittrock'a 

 genus Gonatonema. If placed in Mesocarpus, M. neaumensis 

 diflfers from all the other species with smooth membrane to the 

 zygosperm, in the form of the cells, and in the size and form of the 

 zygosperm, as well as in the mode of conjugation. 



Staurospermum gracillimum Ktz. 



Siphoned. 



Vaucheria sessilis Vauch. Ambleside. 



„ terrestris Lyngb. Pool in slate quarry, Yewdale 

 Fells, Lancashire. 



(Edogoniace^. 



(Edogonium vernale ? Wittr. Furness Fells. 

 „ macrandrum Wittr. Fig, 33. 



Oogonia pear-shaped, three together, 40 ^ in length. Dwarf 

 male as long as length of oogonium, two-celled, attached to the 

 centre oogonium. Furness Fells. 



CEdogonium acrosporum ? dBy. Furness Fells. 

 Bulbochaete setigera Ag. 

 „ pygmaea Wittr. 



