164 MR. A. AND MRS. E. S. GEPP ON MARINE ALGÆ AND 
suspecting it to be an Indian Ocean plant. Mr. Gardiner notes show that his speci- 
mens were dredged up from 45 fathoms ; so presumably Udotea palmetta is a deep-water 
species, a fact which would account for its having escaped observation. U. argentea, 
Zanard., is another interesting species, which has remained unknown since Zanardini’s 
time in consequence of the loss of the type. One of the factors which adds much to the 
interest and importance of Mr. Gardiner's collection is the careful record of the depth 
from which each specimen was obtained, a detail almost entirely neglected until recently 
by collectors. Now that deep-water forms are rendered more accessible by the use of 
the dredge, we are becoming better able to appreciate the range in depth of a given 
species and its accompanying change of form. A good instance of this is seen in 
Avrainvillea amadelpha, of which Mr. Gardiner procured both reef and deep-water 
specimens. Though differing greatly in habit, they are identical in structure; and the 
peculiar dwarfed and mutilated appearance of the reef form is adequately accounted for 
by the eroding action ‘of strong currents or surf. 
The specimens of Caulerpa have been determined by Madame Weber van Bosse, the 
authority and monographer of that genus, who has been so very kind as to examine and 
name all of them, and her report is incorporated in this list. 
The plants of Turbinaria Murrayana and T. ornata are of special interest, inasmuch 
as they show a manner of propagation by stolons hitherto unrecorded for Turbinaria; 
though we believe that this mode of reproduction has been known for some time to 
Madame Weber van Bosse as occurring in the genus. 
We would here offer our best thanks to Mr. Gardiner for entrusting to us the exami- 
nation of this interesting collection, and to Madame Weber for so readily naming the 
specimens of Caulerpa, and also for demonstrating to us the identity of Zonaria 
variegata, a characteristic and widely-distributed species, which is ably treated in one of 
Monsieur Sauvageau’s later papers. To Z. variegata, as we now see, must be referred 
Ralfsia ceylanica, Harv. To Major Reinbold we are indebted for the determination of — 
Boodlea van Bossei and for valuable information concerning Microdictyon derived from 
his MSS., as yet unpublished. We postpone all remarks on geographical distribution 
until the rest of the Algze have been named. 
CHLOROPHYCEZ. 
ULVACEA. 
Urva (Linn.), Wittr., emend. 
l. Urva rascrata, Del. Flore d'Egypte, 1813, p. 153, tab. 58. fig. 5; De Toni, Syll. Alg. 
i. (1889) p. 114. 
Seychelles : Praslin, on reefs exposed at dead low tide. 
Geogr. Distr. Mediterranean. Atlantic. Pacifie. Indian Ocean. 
en in form and structure this plant agrees with Harvey’s specimen from Ceylon, 
no. 100. 
