INDIAN NUDIBRANCHIATE MOLLUSCA. 143 
Guaucus ForsterI, Lamarck. (Pl. XXXIII. fig. 13.) 
Body nearly linear, rather broad in front, and tapering to a fine point behind ; of a 
delicate blue colour, fading into pale grey or violet, with a metallic lustre at the sides. 
Dorsal tentacles very minute, linear, placed laterally, and rather far back. Head small, 
rounded, with minute linear oral tentacles. Branchial lobes three pairs, pedunculate, 
and terminating in a flattened disc set with stout, linear, tapering branchial papille 
round the margin, those in the centre long, and diminishing gradually towards the 
sides ; these, with the disc, are of a deep blue, much darker than the body : the first pair 
are a good deal produced, the posterior pairs shorter, the last nearly sessile. Foot linear, 
dark blue, rather paler in the centre, a little dilated and rounded in front, tapering to 
a slender tail behind. Length nearly 12 inch. 
Glaucus forsteri, Lam. Anim. s. Vert. 2nd ed. vol. vii. p. 448. 
Two or three specimens were brought home. 
This well-known ocean-wanderer, under the names of G. atlanticus and G. forsteri, is 
generally diffused in the seas of warm climates. As in the present instance, the figures 
usually represent it in an inverted position, which has given rise to some mistakes in its 
description. 
Family EOLIDIDA, Alder & Hancock. 
Genus Eouis, Cuvier. 
Body elongate, limaciform, without cloak. Dorsal and oral tentacles linear, non- 
retractile. Branchiz ovate-oblong or linear, arranged in tufts or transverse rows on the 
sides of the back. Anus lateral. Mouth with corneous jaws. Tongue narrow, gene- 
rally with a single longitudinal series of denticulated plates. 
Eouis UNILINEATA, n. sp. (PI. XXXIII. fig. 14.) 
Body rather slender, buff-coloured. Dorsal tentacles moderate-sized, flesh-coloured, 
annulated with six rather distant rings. Oral tentacles long, tapering from a broad 
base, the outline uniting with the line of the head, flesh-coloured below, with yellowish- 
white tips. There is a scarlet line from the centre of the head in front, running back- 
wards between the dorsal tentacles, where it is slightly interrupted, and thence to the 
commencement of the branchiz. Branchial papille rather short and stout, of a pur- 
plish-brown colour, set in five or six indistinct rows or clusters, nearly meeting on the 
back, and terminating a short way from the end of the tail. Foot narrow, rounded in 
front, without lateral angles. Length } an inch. 
Tongue a single series of spines, each with six or seven lateral denticles. Jaws 
narrow, with denticulated cutting-blades. 
The collection contains six specimens. 
VOL. V.— PART III. U 
