DICHOTOMA — ECTOCARPUS. 



51 



little algae, which, I think, is one of the prettiest 

 of the Melanosperms. I do not know whether 

 it possesses any popular name, but its scientific 

 title is Dictyota dichotoma. For a figure of it, see 

 plate A, fig. 5. It is a very delicate-looking plant, 

 and, unlike the Melanosperms in general, lives 

 tolerably well in an aquarium. The name 

 Dictyota is derived from a Greek word, signify- 

 ing a net; and it will be seen, on examination, 

 that the surface of the frond appears as if woven 

 into a tiny network, with square, or rather slightly 

 oblong meshes. Its specific appellation of " dicho- 

 toma" is also of Greek derivation, and signifies 

 "cut in pairs," in allusion to the shape of the 

 frond. 



Failing space permits only one more plant 

 belonging to the class, or rather, to speak accu- 

 rately, the sub-class Melanospermese. This is the 

 plant known to botanists by the title of Ecto- 

 carpus siliculosus, and which I mention here 

 because it is liable to be confused with other 

 algse that much resemble it in form, though not 

 in constitution ; see plate a, fig. 2. It is called 

 Ectocarpus from two Greek words, signifying 



external fruit," and its specific title " silicu 

 losus " is given to it on account of the silicules, 

 or little pod-like bodies, that are found on the 



E 2 



