IOI 



bellata the Flabellaria Pavonia of Lamarck. Lamouroux also adds as a second species, though with 

 some hesitation, Udotea conglutinata [Flabellaria conglutinata Lamarck). He regards them both as 

 animal structures, but takes exception to the view held by Lamarck as to their inclusion among 

 the "Polypiers empatés" and says that all other zoologists agree in regarding them as Corallines. 



In the years that foliowed these publications, the group of Corallines, in which was 

 included the genus Udotea. was mostly regarded as either belonging to the animal kingdom 

 or else was placed among the algae with reservation, as being unconnected with any other 

 family of algae. It remained for Decaisne in his "Mémoire sur les Corallines" in Ann. Sci. 

 Nat. Bot. 2 me série, torn. XVIII. 1842. pp. 96 — 128, and also for Chauvin in his Recherches... 

 Caen, 1842 pp. 124 — 128 independently to lay down clearly and iinally the fact that the 

 Corallines are plants. Decaisne divides them into Zoosporeae (= Siphoneae), Aplosporeae 

 (= Galaxaura, Liagora and Actinotrickia), and Choristosporeae (= Corallinaceae). For Udotea 

 he describes four species, U. flabellata Lamx., U. palmetia n. sp., U. cyathiformis n. sp., 

 and U. Desfontainii (the Flabellaria Desfontainii of Lamouroux). Decaisne gives an account 

 of the structure of the thallus of Udotea, and in his remarks alludes to U. fiabellum under 

 the name of U. pavonia, without however giving the name of U . pavonia as a synonym for 

 U. fiabellum. The genus therefore contained in 1842 only four species. 



We must now return to Chauvin. It is clear that his paper was publishecl after that 

 of Decaisne, for Chauvin in a footnote to his Essai d'une Répartition des Polypiers Calcifères 

 de Lamouroux dans la Classe des Algues (Recherches .... Caen, 1842 p. 124) says: — 

 "Lorsque Ie Mémoire de M. Decaisne sur les Corallines ou Polypiers calcifères a été rendu 

 "public, Ie nótre était terminé ; il a été livré a l'impression tel qu'il avait été composé d'abord". 



Chauvin divided the Polypiers calcifères into two groups onlv - - Zoosporeae and Cho- 

 ristosporeae, placing in the former group Lamouroux's Flabellaria reformed to include the 

 following four species: — 1. F. Desfontainii Lamx. (= Codinni ïuonbranaceuni Ag.); 2. F. 

 finibriata Chauv. (= Codium flabelliforme Ag.); 3. F. conglutinata Chauv. (= Udotea con- 

 glutinata Lamx.) ; 4. F. incrustata Chauv. (= Udotea Jiabellum Howe). His first two species 

 are of course regarded as synonymous nowadays. 



The next connected account of Udotea is given by J. G. Agardh in his Till Alg. Syst. 

 V. 1887 p. 67. This author alludes to the confusion over the two genera of Flabellaria and 

 to other historical details, and gives a description of the structure of various species. He 

 divides the genus into four subdivisions : I. Palmettae, II. Incrustatae, III. Fibuliferae, IV. Cor- 

 ticatae. Among these subdivisions he distributes seven species, one of them, U. peltata, being 

 new to science. Under "Species mini nullo specimine cognitae", he adds 6 names with references 

 and, in four cases, the locality. This summary of Udotea served as the basis of De Toni's 

 treatment of the genus in his Sylloge Algarum (vol. I. 1889 pp. 505 — 5 12) where fifteen species 

 are enumerated, of which six are either doubtful, little known or excluded from the genus. 



Morphological. 



External characters. The thallus of Udotea consists of stipes and frond with or 

 without a root-mass. As a rule, a single stipes arises from the root-mass and bears a single 



