— 194 — 



of the membrane-cells. Here and there towards the hollow in the 

 interior of the thallus some of the cells in the membrane and 

 diaphragms bear some smaller, irregularly star-like cells, provided 

 with acute prolongations. Upon these cells again one or seldom 

 two nearly globular gland-cells occur (Fig. 12 A, B, E). 



The tetrasporangia are formed in the bark-layer and are cru- 

 ciately divided (Fig. 12 G); they reach a thickness of about 25 fx. 



The cystocarps occur scattered over the thallus (Fig. 11 B); 

 they are hemispherically prominent and provided with a small 

 apical porus. 



In the Danish West Indies this plant has only been found 

 once in the sea north of St. Jan: off America Hill west of Tor- 

 tola. It was taken in deep water (about 15 fathoms) and had 

 tetraspores in the month of March. 



It has earlier been found: at Guadeloupe, a cystocarpic plant, 

 leg. Schramm; at the Bermuda Isles from two localities: 

 Ducking Stool, Hamilton, Jan. 1881, and Coopers Island, Febr. 1881, 

 leg. Professor W. G. Farlow and finally from the Canary Islands: 

 Isola di Lanzerote, leg. A. Piccone 14—16 Agosto 1882. 



Champia parvula (Ag.) J. Ag. 



J. Agardh, "Epicrisis", p. 303. Bigelow, "On the Structure 

 of the Frond in Champia parvula, Harv." (Proceedings of the 

 American Academy of Arts and Sciences, vol. XXIII, 1887). M. B. 

 Davis, ''Development of the frond of Champia parvula Harv. from 

 the carpospore" (Annals of Botany, vol. VI, 1892); "Development 

 of the cystocarp of Champia parvula, Harv." (Bot, Gaz., vol. XXI, 

 1890). P. Hauptfleisch, "Die Fruchtentwickelung der Gattungen 

 Ghylocladia, Champia und Lomentaria" (Flora, Bd. 75, 1892). 



I have only found specimens with tetraspores and antheridia. 

 In this species the tetraspores occur as is well known in a broad 

 belt in the middle part of the branches. 



The antheridial stands form small patches of irregularly rounded 

 form dispersed over the surface of the thallus (Fig. 13^). The small 

 spermatia are borne on the tips of short ramified filaments con- 

 sisting of rather short cylindric cells (Fig. 13 B). Such long cells 

 as figured by Davis 1. c, pi. VII, fig. 2, I have not seen in my 

 material. The filaments arise from smaller cells cut off from the 

 thallus cells (Fig. 13 B). 



