THE \I.<;.K OF COMMONWEALTH BAY LUCAS. 7 



Cells above the base cylindrical, o.o1 constricted al the joints. In this region 

 tli.' membrane thick- and usually frayed. Diameter of cells 92/u,. The cylindrical 

 cells are succeeded by oval oblong evils, constricted al the joints, to nearly three times 

 as long as broad, e.g., 400 x 138-6/x. The superior cells more and more inflated, tip- 

 ratio of the length to the diameter gradually decreasing, e.g., 570 \ 276/x, liigher up 

 2,000 x 1,078/i, while the highest may be 2 mm. long with a breadth oi two-thirds or 

 more of the length. 



Membrane conspicuous. Colour (in formalin solution) dull <ireen. 



This species was obtained in great quantity in Commonwealth Bay by dredging. 

 As I never found it attached to any of the other algae collected I think it probably grew 

 on rocks or stones at the bottom. 



It may be compared with Ch. clavata (Ag.) Kuetz from India and South Africa, 

 but the filaments in the latter grow from a Large common attachment, and are much 

 coarser at the base (750^) and are rigid. 



The diagnosis of Ch. coliformis (Mont.) Kuetz suggests somewhat similar 

 dimensions, but is very meagre. ' Filamentis 750/* ad 2 mm. litis, flaccidis : 

 articulis inflatis, latitudine sescpii- ad subtriplo-longioribus. Hab. ad folia Zosterse 

 epiphytica insula? Toud (D'Urville) et Tasmania?." 



Ch. Darwinii (Hook) Kuetz. is much coarser throughout. It is our common 

 southern form. I have specimens from Tasmania and from ('ape Schank, Victoria, 

 in which the upper vesicles attain a diameter of 4 mm. and 5 mm. respectively. Ch. 

 Darwinii often appears with several filaments growing near together, but each attached 



separately to the alga on which it grows. 



On the whole it seems best to label the Eorm Erom Commonwealth Bay, the only 

 locality in which it has been found, as a separate species, conspicuous by the extreme 

 tenuity of the basal tract and the large superior vesicles. 



(Plate 4, figs. 1, 2. 3.) 



FUCOIDE.E (Agardh) J-Agardh. 



Lami.\.\i:iace/E (Bory) Rostafinski. 



I % hyllogigas Sk< ittsberg. 



Phyllogigas grandifolius (A. and E. S. Gepp) Skottsberg. 



This plant was well represented in the collection by a large number of individuals 

 of different stages from very young to the full-grown plant. The series rendered very 



evident the schen e of urowth. 



