— 244 — 



in alcohol; judging from this alone I would have been most inclined 

 to consider them as forms or varieties of the same species only. 



I have found this species growing in rather exposed localities 

 in shallow water and in deep water at a depth of about 30 

 meters. 



It is found: St. Croix, at White Bay; St. Jan, off Cruz Bay. 



Valonia utricularis (Roth) Ag. 



G. Agardh, Species Algarum, vol.1, p. 431. J. Agardh, Till Algernes 

 Systematik, VIII, p. 98. P. Kuckuck, Über den Bau und die Fortpflanzung 

 von Halicystis Aresen, und Valonia Ginn. (Bot. Zeit. 1907). 



Conferva utricularis Roth, Gat. I, p. 160, tab. 1, fig. 1, Gat. II, p. 187. 



forma typica Kuck. 1. c. 

 forma Crustacea Kuck. 1. c. 



The forms I have referred to this species seem to agree very 

 well with those described by Kuckuck , 1. c. In the forms which 



occur on exposed places, the small 

 lens-shaped cells were present in great 

 number. They occurred not only in 

 the basal part of those cells by which 

 the plant is fastened to the substra- 

 tum, but also in other parts of the 

 cells, especially in the furrow where 

 the cells meet each other. Here we 

 often find a dense row of these small 

 cells on both sides of the wall and 

 as these small lenticular cells often 

 bear short rhizoids which attach them- 

 selves to the neighbour cell they con- 

 tribute to the firmness of the cell- 

 complex, making it more resistant to 

 the beating of the waves. 



Fig. 2 shows a plant of the form 

 I have referred to var. Crustacea and fig. 3 a little part of it more 

 magnified. The arrangement of the lens-cells and the manner in 

 which the rhizoids, growing out from the small cells, attach them- 

 selves to the neighbouring cells reminds one in a striking way of 

 Dictyosphœria favulosa, a plant I also consider very nearly related 

 to Valonia, as will be mentioned later on. 



Fig. 2. 



Valonia utricularis (Roth) Ag. 

 forma Crustacea Kuck. 



(about 6 : 1). 



