o'donoghue : nudibranchiate mollusca. 14:5 



20. Ibid:, " Descriptions of Nudibranchiate Mollusca inhabiting Polynesia " : 

 Amer. Journi Conchol., vol. vi, 1871, p. 299. 



21. Vayssiere, A., " Recherches zoologiques et anatomiques sur les Opistho- 

 branches de la Mer Rouge et du Golf d'Aden " : Ann. Fac. Sci. Marseilles, 

 vol. XX, supp., 1912. 



VI. On Fiona marina, Forskal. 



The history of the nomenclature of the species now known as 

 Fiona marina is a varied one, and has not, I think, been fully set 

 forth. It is of interest since it is one of the first three forms to be 

 recorded from this region. 



One of the first nudibranchs to be described in a manner that 

 enabled it to be recognized subsequently was Limax mariniis, which 

 was reported by ForskEl (17, p. 99) in 1775. 



Van Ilasselt, in a letter to Professor van Swinderen dated 

 25th May, 1823, from Tjuringe, Java, but first published in 1824 

 (18, p. 22, and 19, p. 238), described what he presumed to be a new 

 species Eolidia alba. 



Eschscholtz (15, p. 14) in 1831, furnishing the first account of the 

 Nudibranchs from the Pacific Coast of North America, included the 

 record of an Eolidia pinnata, examples of which were collected by 

 Captain von Kotzebue at Sitka, Alaska, in 1824. 



Quoy et Gaimard (20, p. 288), in 1832, described an ^olis 

 longicauda from New Zealand waters. In 1857 Alder and Plancock 

 (1, p. 291) recorded a new form which they teimed Oithona nohilis, 

 and claimed it not only as a new species, but also as the type of a 

 new genus. In Forbes and Hanley's " British Mollusca " (16, p. x) 

 we find a footnote : " Mr. Alder and Mr. Hancock inform us of their 

 intention to substitute the generic name Fiona for Oithona (Fam. 

 Eolididse), the latter appellation having been previously employed 

 by Dr. Baird for a genus of Entomostraca." This was established 

 more permanently by these two writers in 1855 (3, pp. 52-53). 

 In the latter paper, also, they made it not only the type of a genus 

 but also of the Family Fionidaa, an arrangement subsequently 

 accepted and adopted by Eliot (14, pp. 75 and 166) in 1910. 



The establishment of the genus Fiona was also accepted by Bergh, 

 w^hen in 1858 (4) he described a form as Fiona atlantica, and again 

 in 1859 (5) and in his subsequent papers. Generic rank is 

 undoubtedly deserved by these forms, since, while they resemble 

 the ^olidida superficially, they difier in certain important respects 

 and are easily recognizable. The genus is to be distinguished by 

 the presence of a gill lamella or membrane running down the side of 

 each of the cerata ; the anus is dextro-dorsal in position ; the 

 apertures of the genital ducts are separate ; the dorsal margin 

 forms a rudimentary flap ; the jaws are denticulate ; the radula is 

 uniseriate, and the oral tentacles are set far back. 



In 1866 (13, iii, pp. 64-80) and in 1867 Costa (13, iv, p. 28) 

 described a species from the Mediterranean Sea under the name 

 HymencBolis elegantissinia, but this is obviously a Fiona. 



