46 

 REVIEWS 



The Marine Alg'ae of the Danish West Indies* 



Students of the marine algae in general and more especially 

 those interested in the study of the American marine algae will 

 find much of value in Borgesen's copiously illustrated account 

 of "The Marine Algae of the Danish West Indies," of which 

 Parts I and 2, dealing with the Chlorophyceae and Phaeophyceae, 

 have already appeared. This critical report is based chiefly 

 upon material collected by the author on three visits to these 

 islands, made in 1892, 1895-96, and 1905-06, though he has had 

 access also to earlier collections made by West, Orsted, and 

 others. Bdrgesen had good success in dredging at various 

 points, though here, as in most other parts of the West Indies, 

 the nature of the sea-bottom, owing chiefly to the local abundance 

 of corals, is often unfavorable to dredging operations. 



Of the Chlorophyceae, Borgesen recognizes 86 species as oc- 

 curring in the Danish West Indies. These 86 species are con- 

 sidered to represent 34 genera, of which the largest are Caulerpa 

 with II species, Chaeiomorpha, Cladophora, and Udotea, with 6 

 each, Enteromorpha and Halimeda, with 5 each, and Avrainvillea, 

 Codium, Penicillus, and Valonia, with 4 each. In comparing 

 the rich chlorophyceous flora of the tropics with the poorer 

 representation of this group in northern waters, Borgesen re- 

 marks that whereas on the shores of Danish West Indies he found 

 several kinds of green algae growing in abundance at a depth of 

 about 20 fathoms, in the Faeroes (Lat. about 62° N.) he found 

 only a few red algae at such depths, most of the Chloroph^'ceae 

 not descending below the uppermost part of the sublittoral 

 region. As novelties of the specific rank, Borgesen in Part i 

 describes and figures Pringsheimia(J) Udoteae, Cladophora un- 

 cinata, C. corallicola, and Avrainvillea Geppii. Belonging in this 

 category also, though first described and figured by him in 

 various preliminary papers, are Enteromorpha chaetomorphoides ^ 

 Dictyosphaeria van Bosseae, Striivea elegans, Avrainvillea asari- 



* Borgesen, F. The Marine Algae of the Danish West Indies. Part i. 

 Chlorophyceae. 1-158. /. j-J2(5 + c/zar^. 1913; Part 2. Phaeophyceae. 159-222. 

 /. 127—170. 1914. Issued separately, with Part 2 repaged, from Dansk Bot. 

 Arkiv I*: 1-158 and 1-: 3-66. 



