— 270 — 



This species occurs in shallow water often in rather exposed 

 localities. 



It is found, St. Thomas: in the Harbour and in the Great 

 Northside Bay on the north side of the island. 

 St. Croix: Christianssteds harbour. 



Chamædoris Mont. 



C. Peniculum (Sol.) O. K. 



Corallina Peniculum Solander in Ellis, The Natural History of many 

 curious and uncommon Zoophytes collected from various parts of the globe, 

 London 1786. p. 127, tab. 7, fig. 5— 8, tab. 25, fig. 1. 



Chamædoris annulata (Lamarck) Mont. Montagne, Troisième centurie 

 de plantes cellulaires exotiques nouvelles (Ann. des se. nat., II. Sér., 1. 18, Octo- 

 bre— Nov. 1842. Harvey, Nereis Bor .-Am. part III, p. 42, tab. 42 B. J.Agardh, 

 Till Algernes Systematik, VIII, Siphoneæ, p. 113. 



Nesea annulata Lamouroux, Histoire de Polypiers coralligènes flexibles. 

 Caen 1816, p. 256. 



Penicillus annulatus Lamarck in Ann. du Muséum, t. 20, 1813, p. 299. 



Scopularia annulata Chauvin, Pvecherches sur l'organisation, la fructifi- 

 cation et la classification de plusieurs genres d'Algues. Gaen 1842 (9. Nov.). 



As is well known from the description of Harvey (I.e. p. 42) 

 the thallus of this plant, when fully developed, consists of the 

 nearly cylindrical stem with annular constrictions from base to top 

 where it ends in the cup-shaped head, giving the whole plant a 

 mop-like appearance. When living the stem has a more or less 

 striking red-violet colour and is rather phosphorescent, the head is 

 dark-green on the outer side lighter grey-green on the upward 

 turned side. 



At its base (Fig. 16) the stem is fastened to the substratum 

 by irregularly branched and septate rhizoids which penetrate often 

 rather deeply into the loose limestone, upon which especially I 

 have found the plant growing. In the cells of the rhizoids starch 

 is richly present. The uppermost rhizoids growing out from the 

 stalk are more rhizome-like, creeping as they do on the surface of 

 the substratum, and from these new stems grow up often in great 

 number. Owing to this mode of growth the plant also grows gre- 

 gariously often in large tufts. How far all the individuals in a tuft 

 have their origin from this mode of propagation I cannot say; 

 many of the plants in a tuft were so 1 loosely connected and so 

 easily separated that one may doubt their origin in this way, but 



