462 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



151. Cladocephalus luteo-fuscus, filaments of cortex, after Bor- 



gesen. 100 X i. 



152. Derbesia marina, frond with sporangia, after Saunders. 



40 X i ; zoospore, after Solier. 300 X i. 



153. Vaucheria Gardneri, after Gardner. 100 X i. 



154. Udotea cyathiformis, after Harvey, i X i. 



155. Bryopsis plumosa, after Kiitzing. 20 X i. 



156. Halimeda Opuntia, after Gobel. i X i. 



157. Phyllosiphon Arisari, surface view, after Kiihn. 40 X i. 



PLATE XVIII. 



158. Dichotomosiphon tuberosus, with oogonia and antheridia, 



after Ernst. 50 X i. 



159. Ostreobium Quekettii, after Bornet and Flahault. 25OX i . 



160. Caulerpa prolifera, after Reinke. i X i. 



