258 THE SLENDER CORYNE. 



cylindrical footstalk of a Rhodymenia, about which 

 it creeps irregularly in the form of a white thread, of 

 about the same thickness as a human hair, as I found 

 by placing both beneath the microscope together. 

 This thread is cylindrical and tubular, perfectly hya- 

 line, and without any vestige of rings or wrinkles, 

 but permeated by a central core apparently cellular in 

 texture, and hollow, within which a rather slow circu- 

 lation of globules, few in number and remote, is dis- 

 tinctly perceived. The thread is very long in pro- 

 portion to its thickness, and here and there starts 

 from the support and sends off free branches, or 

 rather divides; the ramifications generally forming 

 an acute angle, and continuing of the same thickness, 

 form, and structure as before. Some of the branches 

 send off others, some soon form the terminal head, 

 others run to a great length, even to ten-times the 

 the length of the head. This excessive length and 

 tenuity of the branches constitute a character very 

 unlike that of C. ramosa. (See Plate XVI. figs. 

 1-5). 



The polype-head appears to be a clavate enlarge- 

 ment of the branch, no open end of an investing tube 

 being visible in any part of the zoophyte. The head 

 is oblong, usually cylindrical, rounded at the end^ 

 but sometimes considerably ventricose in the middle ; 

 and wherever this form occurred, I invariably found 

 a large bubble of air in the midst of the swollen part. 

 The head is transparent, slightly tinged with yellow- 

 ish; corrugated with coarse annulations. The core 

 of the stalk enters into its lower part, and soon dilates 

 into a semi-opaque granular mass, becoming more 



