240 Transactions. — Botany. 



C. gemmiferum, Brebisson. S. 



Fig. 4. 



A large, handsome species, of the general appearance of C. margariti- 

 ferum, covered with conspicuous pearly granules, but differing by having on 

 each segment, at the middle, on both surfaces, a rounded protuberance 

 bordered with granules, which is best seen in end view. (Pritch. Inf., 

 p. 733.) 



The typical plant has slightly truncate ends ; in our species the trunca- 

 tion is sometimes not apparent. 



Seemingly not uncommon in Hawke's Bay. The European species has 

 only been found, I think, in France. 



C. obsoletum, Hantzsch, var. punctatum, var. nov. S. 



Fig. 5. 



Frond in front view almost circular, the breadth perhaps a little more 

 than the length. Edge smooth. Constriction deep, narrow, linear. Seg- 

 ments broader than long, with a minute, bluntly-triangular process on 

 each at the entrance of the constriction on each side ; processes convergent, 

 pointing slightly outwards. End view elliptic, showing the processes. 

 Surface of frond distinctly puuctate. Diameter in front view, 60-65 ft. 

 Zygospore unknown. 



Not uncommon in gatherings from Hawke's Bay. 



Professor 0. Nordstedt, in a paper which he has kindly sent me on some 

 Alga? in the museum of Lund, figures a species from Java — C. obsoletum, 

 Hantzsch, closely resembling the above. The same plant is found in 

 Babenhorst (Flor. Alg., sect, iii, p. 227) as Arthrodesmus obsoletus, a variety 

 of A. convergens. Neither author, however, gives more than the very briefest 

 description. But Prof. Nordstedt's figure clearly shows his plant quite 

 smooth, without puncta. In other respects I see no difference, and I think 

 the puncta are not sufficient to raise our plant above the position of a 

 variety. 



C. speciosum, Nordstedt, var. infiatum, var. nov. 



Fig. 6. 



Frond in front view elliptical, the ends not at all or very slightly com- 

 pressed ; segments longer than broad, sides convex ; constriction deep, 

 narrow, linear. Segments when empty showing rows of minute semi- 

 orbicular granules, the rows apparently radiating from the centre of each 

 segment, but not reaching quite to it, so that the median space would be 

 smooth if it were not for a number of longitudinal rows of smaller granules, 

 which rows, being slightly curved and not all in focus at once, testify to the 

 presence of a central inflation. The result of the two sets of granules is to 



