17 



in the Sloane Herbarium in the British Museum (vol. 232, fol. 18), and was described in 

 MS. by Solander in the British Museum copy of Ray's Hist. III. Suppl. p. 1 2 1 704 as 

 "Fucus bahamensis flabelliformis" — a diagnosis which also includes Udotea flabellum. 



The next species of which we can find any record was published in 1S23 by C. A. Agardh 

 (Spec. Alg. p. 401) as "? Anadynomene oóscura", collected by Gaudichaud in Guham, one of 

 the Marianne Islands. It was transferred in 1887 to Avrainvillea by the late J. G. Agardh 

 (Till Alg. Syst. V. p. 53), in whose herbarium at Lund it is preserved. We have not been 

 able to examine the actual specimens and are therefore in some doubt as to whether it may 

 not prove to be synonymous with A. erecta, in which case its specific name would take 

 precedence of erecta (see p. 33). 



Nineteen years later (1842) two French authors, Decaisne and Chauvin, working 

 independently upon the Polypiers Calcifères (calcareous algae) to determine conclusivelv their 

 vegetable or animal nature, which theretofore had been a disputed question, published their 

 respective results within a few months of one another, Decaisne's publication (Ann. Sci. Xat. 

 2 me sér. torn. XVIII. 1842. p. 107) appearing first, as is acknowledged by Chauvin in a footnote. 

 In ter alia, Decaisne described his new genus Avrainvillea, with one species A. nigricans, 

 collected by d'Avrainville in the Hes des Saintes, Guadeloupe. The type of this is now in 

 Herb. Mus. Paris. Chauvin (Recherches ..., Caen, 1842, p. 124), who arrived at conclusions 

 similar to those of Decaisne as confirming the vegetable nature of the Polypiers calcifères, 

 also defined a new genus, which he named Fradclia and founded upon F. fnliginosa, an alga 

 collected at Pernambuco by Fradel ("sur Ie récif de Pernambouc"). His description of it and 

 his remarks are so clear as to justify its being placed under A. nigricans Decaisne, notwith- 

 standing the vast distance which intervenes between the respective stations of Fradelia and 

 A. nigricans, amounting to over 2000 miles. The question of its actual identity can only 

 be settled by an examination of the type, for Chauvin omitted to give the diameter of 

 the filaments. 



In the same year (1842) Berkeley (Hooker's London Journal of Botany I. p. 157) 

 described as a fungus in the genus Dichonema, calling it D. crectnw, the plant n° 2234 

 collected by Cuming in the Philippine Islands. The figure of it is bad, but was sufficiënt to 

 lead us to suspect that it must be the same as the Udotea sordida described by Montagne 

 (Hooker's London Journal of Botany III. 1S44 p. 659) two years later from Cuming's n° 2233. 

 Our suspicion proved correct. Further notes on this point are given under Avrainvillea erecta 

 (p. 30). This latter species has hitherto been best known under the name of A. papudna 

 Murr. & Bood. 



In 1857, Montagne (in Ann. Sci. Xat. vol. VII. 1857 p. 136) described Udotea amade lp ka, 

 a unique specimen collected by Le Duc at the island of Galega in the western Indian Ocean. 

 This species remained in neglect until we gathered together material for the present paper 

 and found the type specimen to possess the structure of Avrainvillea and not of Udotea. 

 More recently we have found other examples of the plant in the collections of Mr. J. Stanley 

 Gardiner from the western islands of the Indian Ocean, as we have lately recorded in Trans. 

 Linn. Soc. (Bot.) VII. 1908 p. 178 and further we have 110 doubt at all that the Red Sea 



SIBOGA-EXrEDITlE LXII. •; 



