F. Børgesen: Rhodophyceæ of the Danish W. Indies. 391 



The growing point in the apex of the thallus consists of numer- 

 ous filaments packed together and with diverging apices. 



A transverse section (Fig. 374 a) of the thallus shows at the 

 periphery a single row of oblong cells placed densely together; 

 these cells are about 28 fj. long and 16 /i broad. Next to this layer 

 a parenchymatic tissue follows whose cells are roundish and gra- 

 dually increase towards the cavity being at the same time 

 somewhat looser connected. The innermost cells protrude more 

 or less freely into the cavity and carry now and then glands (Fig. 

 374 a) 



A longitudinal section (Fig. 374 b) shows that the peripheral 

 cells are nearly square ; the cells of the parenchymatic tissue are 

 rather long, about 2 — 3 times as long as broad. 



The specimens examined were sterile; I thought in one of 

 the specimens to have found tetrasporangia, but a more thorough 

 examination showed that these originated from a Hypnea whose 

 filaments were densely interwoven between those of Coelothrix. 

 But Collins*) mentions having found tetraspores, and Howe**), 

 too, mentions such ones. According to him "the tetrasporangia 

 occur on pod-like enlargements of the ends of certain branchlets". 

 Collins also mentions having found cystocarps; these "are spher- 

 ical and external on the branches". A more detailed description 

 of these organs would be highly desirable. 



In "The Algæ of Bermuda" Collins and Hervey name the 

 plant Cordylecladia rigens, referring it to the Chylodadia rigens 

 J. Ag. <"= Sphærococciis rigens C. Ag.). Howe, 1. c, p. 516 points 

 out that "the type of Sphærococcus rigens Ag. is a Japanese plant 

 different in structure from the Bermudian and West Indian." 



The specimens preserved in the Botanical Museum, Copen- 

 hagen, are partly "ex ins. St. Crucis, misit Palle Bang", partly 

 from "St. Jan., Dr. Ravn." They are labelled Sphærococcus duriis 

 Ag. var. 



Geogr. Distrib.: Florida, Bermuda, Jamaica. 



*) Collins, Fr. S., The Algae of Jamaica (Proceed. Am. Acad, of Arts 

 and Sciences, vol. 307, 1901, p. 255). 

 **) Howe in Britton, Flora of Bermuda, 1908, p. 516). 



