A NEW SPECIES OF ALC4A CONFERVA THERMALIS BIRDWOODII. 137 



I found four varieties of Alga3 in the different springs about the 

 place : — 



(1) A species of Ulothrix, not very different in structure from 



Ulothrix Radicans of Cooke. 



(2) A species of Nostoc with its very minutely beaded appearance. 



(3) A Conferva very similar to C ' hcetomorpha implexa {vide 



p. 140, Cooke's Algte, plate 54, fig. 6). 

 These three varieties will by and bye receive special treatment 

 at my hands, but to-day I propose to examine in detail the fourth 

 species of Conferva which I have not seen described anywhere in 

 Kiitzing, Cooke, Hassall or Mrs. Gatty. 



(4) To the naked eye this variety of Conferva is visible in the 

 shape of fine hairy filaments of beautiful rich green. Under the micros- 

 cope with a 5 inch objective the structure is seen in detail, and is not 

 unlike that of Enteronwrpha Percursa described and figured by 

 Mrs. Alfred Gattv in her British Seaweeds under No. 350, Plate 

 LXXII, the difference being that our specimen has distinct 

 dissepiments in the body of the Alga and tretrasporous 

 arrangement of the zoospores inside the tubular segments. 

 Following Mrs. Gatty 's mode of description given in her work, I 

 here briefly give the result of my examination of the newly- 

 discovered Alga. 



Color. — Bright rich green when in the hot water ; turning olive 

 green on being kept in cold water, or on drying. 



Substance. — Soft ; can be easily torn off. 



Character of frond. — Single ; bearing occasionally slender spine-like 

 branchlets, short and tapering, not distinctly jointed, growing in tufts. 



Joints.— Small, numerous, faintly marked, with from four to six 

 dissepiments in the long axis of the Alga. Smaller horizontal joints 

 separating the endocbrome and zoospores into spaces j~ to ^-^ 

 inch in length and -p^ inch in breadth. 



3Itasuremeuts. — 4 to 6 inches high when standing in the hot stream 

 in tufts. 



Fructification. — Unknown. In some of the mature segments the 

 central mass of coloring matter constituting the sporidium is arranged 

 in a tetrasporous manner, the contents escaping in due time, probably 

 by rupture of the segment walls. 



As the species is q>ite a new one, requiring a designation, I have 

 obtained the Honorable Mr. Justice Birdwood's permission to 



