239 



NOTES ON TWO EAEE BRITISH NUDIBEANCHS, HERO FOEMOSA, 

 VAR. ARBORESCENS, AND STAURODORIS MAGULATA. 



By Sir C. N. E. Eliot, K.C.M.G. 



Read IZth January, 1905. 



I. Hero foemosa, var. arboeescens, var. nov. 



Hero formosa, Loven, G. 0. Sars : Moll, regionis areticse Norvegiae, 



p. 316, pi. xxviii, figs. ^a-Zd ; Bergh, Semper's Reisen, Heft vii, 



p. 310; Verhandl. zool.-botan. Gesell. Wien., vol. xxxviii,p. 699, 



pi. xix, figs. 9-11 ; pi. XX, figs. 1, 2 (1888); Vayssiere, Ann. 



Mus. Marseille, vol. iii, p. 88 (1888). 



Hero is a somewhat aberrant genus of the ^olidiidse, differing 



from all the others in having branched cerata, one pair of which is 



situated on the frontal margin before the rhinophores. The radula 



is triseriate. The known species are confined to the North Atlantic 



and Mediterranean. Bergh (Syst. Nud. Gast., Semper's Reisen, 



Heft xviii, p. 1037) gives four, but of these E. Mediterranea (Costa) 



appears to be founded on a misprint. Costa, in the Ann. del Mus. 



Zool. della R. IJniv. di Napoli, 1866, p. 41, gives, in a list of fauna, 



" Cloelia (a synonym of Hero) Mediterranea, Nob. Golfo di Napoli, I.," 



but on p. 90 of the same publication, under the heading " Alcune 



correzioni ed aggiunzioni," we read, "pag. 41, verso 12, Cloelia, leggi 



Tenellia." The species, therefore, is not a Hero at all, but the Tenellia 



Mediterranea described by Costa in the same paper, which is perhaps 



an Emhletonia. Hero jimbriata is the Doris firnhriata of Vahl (Miiller, 



Zoologia Danica, 1788, vol. iv, p. 22), described as " Boris flavescens, 



pedicellis dorsi apice fimbriatis," and depicted on pi. cxxxviii, fig. 2, 



which represents a yellow and pinkish animal, with slightly branched 



processes on the sides of the back and frontal veil. It seems to me to 



be a Tritonia or Marionia. 



Two valid species are known — H. formosa, Loven, from the Northern 

 Atlantic, and H. Blanchardi, Vayssiere, from the Mediterranean. The 

 former is yellowish white, with opaque white lines and spots ; both 

 the frontal and the lateral papillae are ramose, and the central tooth of 

 the radula has three or four denticles on each side. H. Blanchardi 

 is yellowish, with red papillae ; the frontal papillae are ramose, but 

 those at the sides of the body are small, and either entire or simply 

 bifid ; the central tooth of the radula has five denticles. 



I have received from St. Andrews three specimens which seem to 

 constitute a well-marked variety of H. formosa, possibly meriting 



