





TILE AUiM OF COMMONWEALTH HAY. 



By A. II. S. Li .as, M.A. Oxon., B.Sc, Lond. 



CHLOROPHYCE^ (Kuetz ex parte) Wittroch. 



Ulvacete (Lamouroux) Rabenhorst. 



Prasiola C. Agardh. 



Prasiola crispa (Lightfoot ) Agardh. 



Many packets of this plant were gathered by Mr. J. (J. Hunter, in both winter 

 and summer months, at heights of from 20 to 50 feet above sea-level, in the neighbourhood 

 of Commonwealth Bay. 



His records are : — 



March 30th, 1912.— Found on soil mainly composed of penguin guano on leeward 

 side of ridge of gneissic rocks, and so protected from S.S.E. blizzard winds, 

 30 feet above sea-level. 



June 21st, 26th, 1912.— Found in crevices of rocks and covered with snow, 20 feet 

 above sea-level. 



July 21st, 1912. — Found on an old penguin rookery in crevices of rocks, 40 feet 

 above sea-level. 



Dec. 2nd, 1912. —Specimens obtained from moraines 30 feet above sea-level. 



Dec. 15th, 1912.— From 30-50 feet above sea-level. 



Dec. 21st, 1912.— 20 feet above sea-level. 



It was also gathered in a locality 120 nuies E. of the winter quarters, Adelie 

 Land, by Dr. A. L. McLean. 



The stratum of Prasiola was a few mm. thick, to 5 or G mm. in the dried s1 

 and consisted of many layers of the thalli of the alga. The fronds when examined 

 under the microscope show r ed great variety of form, from orbicular to long Stigeonema- 



like bands, and were often completely irregular in shape. 



The cells before division varied considerably in dimensions, bu1 a good average 

 of them were oblong-quadrangular, about 11/x x 5/x. Kuetzing made a separate 

 species of the Antarctic form obtained by Hooker at Cockburn I., the larger cells 6/x 

 (about) in diameter, with interspaces wider than the endochrome of the cells. Our 

 dimensions agree better with those of P. crispa, and the interspaces are not markedly 

 wide. J. Agardh comments on a difference in habit. P. antaretica appearing on moist 





