F. KITTON ON DIATOMACEARUM DILLWYNII. 171 



the latter magnified 3,000 diameters (?) is very much like Dillwyn's 

 figures of C. nummuloides. — F. K.) 



G.fcetida. — C. filamentis ramosis, flaccidis, vergatis coadunatis, 

 apicibus liberis, ramis consertis sub-dichotomis dissepimentis 

 obsoletis articulis longinsculis granula elliptica solitaris includien- 

 tibus. 



Ulva ftetida, Vaucher, " Histoires des Confervas " d'eau douce, 

 p. 244, t. 17, f. 3. Monema Dillwynii, Grev. ; Schizonem a Dill- 

 wynii, Sin. ; Berkeleyi Dillwynii, Gran. Stagnant pools in the salt 

 marshes of Cley, Norfolk, Mr. Hooker ; Bantry Bay, the Mumbles 

 Lighthouse, Glamorganshire. 



In the early part of last June (1808) I discovered this curious 

 production of nature growing under the Mumbles Lighthouse in 

 a pool left by the tide near low water mark, where, had not the 

 tide receded unusually low, it could not have been exposed to view. 

 This I suppose to be a natural situation, but I have since learnt 

 that Mr. Hooker had gathered it two months before in the salt 

 marshes above mentioned, and had ascertained it to be the plant 

 described and figured by Vaucher ... I have not ventured on 

 introducing it as a vegetable without considerable hesitation on 

 account of its strong peculiar oily smell, resembling that of some 

 zoophytes, but the eye, even when assisted with the highest powers 

 of a microscope, cannot discover any appearance at all sufficient to 

 distinguish it from the tribe with which it is now arranged. 



C. fcctida grows in thick bushy tufts near two inches in length. 

 . . . The filaments are very flaccid, and peculiarly slender in pro- 

 portion to their length. They are twice or three times branched 

 in an irregularly dichotomous manner. . . The length of the 

 joint is nearly double the diameter. Each joint contains an egg- 

 shaped mass resembling C. jngalis (==Zygnema deciminum, Agh.), 

 w r hich, from analogy, I suppose are formed by a collapsion of their 

 joints or internal granules, and are somehow connected with fruc- 

 tification, as supposed by Vaucher, but, like him, I have had no 

 opportunity of investigating the matter. 



(This description well illustrates the very imperfect state of the 

 microscope at the time Dillwyn wrote the above description. The 

 so-called joints he, of course, did not see, and simply assumed their 

 presence because he had detected them in the other Conferva:. I 

 append Vaucher's description of this form, which agrees very fairly 

 with that of Dillwyn. — F. K.) 



