47 



Desfontain). As is shovvn under Udotca (p. ioo) Lamarck published in the very next paper to 

 Lamouroux's and in the very same volume a nevv genus also called Flabellaria for the recep- 

 tion of Ellis and Solander's two species Corallina conglutinata and C. Flabellum, together 

 with some species which now belong to Halimeda. Lamarck regarded his Flabellaria as a 

 genus of animals. In 1842 Decaisne (Ann. Sci. Nat. Bot. 2 me série, torn. XVIII. pp. 96 — 128), 

 having demonstrated the Corallines to be plants, included both Flabellaria of Lamouroux and 

 Flabellaria of Lamarck in the older genus Udotea Lamouroux (181 2). From 1842 onwards, 

 with a few exceptions which are noted in the list of synonomy of F. petiolata, that species has 

 always been classed with Udotea, but we now feel ourselves compelled to remove it from that 

 genus and place it with U. minima in its old genus Flabellaria, for reasons which we give 

 under F. minima on p. 48. 



Flabellaria Lamouroux 1813 (non Lamarck) 

 in Ann. Mus. d'Hist. Nat. Paris vol. XX. 1S13. p. 274. tab. 12. fig. 4. 



Syn. Udotea auctorum, pro parte. 



Plants green, uncalcified, springing from a rhizome and consisting of caespitose filaments 

 (as in Chlorodesmis comosa) or stipitate fronds. Rhizome colourless, horizontal, monosiphonous, 

 branched, radicelliferous. 



Stipes usually simple, occasionally forked, green, very rarely calcified below, composed 

 either of a few parallel, slightly twisted, uncorticated dichotomous filaments, or of a few main 

 filaments bearing lateral branchlets subdivided into numerous short, truncate, cylindric apices 

 crowded together into a cortex. 



Frond flabellatorotundate from a cuneate base, thin, faintly zonate, proliferous, margin 

 subentire to ciliate. 



Frond filaments monostromatically to distromatically arranged, subcontiguous, radiating 

 from base to margin, either free or slightly held together by a few lateral branchlets or closely 

 covered by a well-developed monostromatic cortex composed of the interlocked sinuate and 

 lobulate apices of the lateral branchlets. 



Zoosporangia doubtful, described as lateral, globose, sessile on filaments of frond. 



Synopsis of Species. 



Plant dimorphic ; filaments either arising free in caespitose tufts from the rhizome 

 or uniting to form elementary uncorticated stipitate fronds, often composed 

 of entirely free filaments F. minima. 



Plant consisting of a stipes and frond, both corticated, but margin of frond some- 



times ciliated and without cortex F. petiolata. 



1 . Flabellaria minima nov. comb. 



Syn. Udotea minima Ernst in Beiheft zum Botanischen Centralblatt XVI. 1904. p. 199. t. 7, 8. 

 Udotea minima Lotsy Vortrage Bot. Stammesgeschichte I. Jena 1907. p. 61. fig. 3$. 



Hab. MEDITERRANEAN, Posilipo, Porto della Villa Rendel, on harbour wall, March 1902, A. Ernst. 



