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Show 6 4 6 SIR C. ELIOT ON NUDIBRANCHS [June 19, to examine the specimen from Ceylon described by Farran as Platydoris ? spinulosa, but doubt if it is referable to this genus. P latydoris Formosa (A. & H .) . (Plate XLVII. fig. 3.) (Doris formosa A. & Ii. 1. c. p. 116. Eliot, Proc. Zool. Soc. 1903, ii. p. 376.) Two specimens * are preserved, one about 60, the other about 40 mm. long. They agree with Alder and Hancock's description and plate. The back is smooth, and the minute granulations are visible only with difficulty even under a lens. But scattered over the larger specimen quite irregularly are a number of hard white tubercles which look like parasitic growths or accretions. They are not detachable, and there are none on the smaller specimens. The lobes of the branchial and rhinophorial pockets are very distinct. The foot is grooved and deeply notched in front. The oral tentacles are rather large, and so distinctly grooved on the outer side as to be almost ear-shaped. The tissues of the radula have decayed, but the teeth are well preserved. They are hamate, with moderately stout bases and rather slender elegant shafts which often have a distinct ridge or wing at the side. They differ considerably in size and somewhat in shape, some being more strongly hooked than others, but it is not now possible to assign them to their respective places in the radula. Alder and Hancock say they decrease in size towards the centre. It is noticeable that no denticulate or degraded teeth are to be found, so that the hamate form is probably retained to the extreme end of the rows and does not degenerate, as so often happens in Platydoris. The genitalia are much hardened, but it is still plain that the large efferent ducts of both branches are extremely strong and muscular. One tube (probably the vas deferens) is thickly set with large round granulated scales, bearing short strong spines (PI. XLVII. fig. 3). The other tube (probably the female branch) is lined with very conspicuous folds and lumps. This handsome species appears to be characterised by its coloration, its distinctly grooved tentacles, and the armature of the genitalia, particularly the granulated appearance of the discs. The East African form referred by me (I. c.) to this species with a query does not agree with the type specimen, and is more likely to be PI. sanguinea Bergh (Siboga, p. 139). P latydoris scabra (C uv.). - Doris coelestis Kelaart. (Quoy & Gaimard, Voyage de 1'Astrolabe, Zoologie, tome ii. p. 258. Eliot, Proc. Zool. Soc. 1903, ii. p. 375. Kelaart, 1. c. I. p. 293.) The Doris coelestis of Kelaart seems to be clearly the older These and all the specimens described by A . & H. in Trans. Zool. Soc. 1864 are carefully labelled by Hancock, so that there is no doubt of their identity. |
