116 MESSRS. ALDER AND HANCOCK ON 
Genus Doris, Linnéus. 
Body depressed ; cloak covering the head and foot. Dorsal tentacles laminated, re- 
tractile. Oral tentacles variable. Branchie plumose, surrounding the vent in the 
medio-dorsal line, and retractile within a common cavity. Tongue broad, with nume- 
rous spines in each row. 
Doris Formosa, n. sp. (Pl. XXIX. figs. 1, 2, 3.) 
Body oval, much depressed. Cloak coriaceous, very ample and with the edges 
deeply sinuated ; yellowish-olive-coloured, beautifully marbled and blotched with scarlet, 
and minutely freckled with dark brown; under side white, with large scarlet-orange 
spots and blotches, with a minute dark freckling near the foot, and pale minute trans- 
verse lines, indicating probably the presence of muscles. Dorsal tentacles clavate, 
yellowish ; the margins of the orifices a little raised and whitish, spotted with brown. 
Oral tentacles linear, rather stout, with the dorsal surface grooved, giving them a folded 
or ear-like appearance ; freckled with brown. Branchial plumes six, tripinnate ; the 
margin of the cavity produced into six lobes or leaf-like processes, which fold down 
over the branchie when retracted; they are white, with conspicuous brown spots. 
Foot rather narrow, dilated in front, where it is laminated and deeply notched, and 
rounded posteriorly ; it is white, with minute brown freckles over the surface. Length 
34 inches. 
Some individuals have the markings much fainter, with the spots on the under side 
yellow. 
The tongue (as in most of the species here described) is similar to that of the com- 
mon Doris tuberculata of Cuvier: the lateral spines in each transverse row are very 
numerous, smooth, stout, and strongly hooked, diminishing in size towards the centre, 
and without a central spine. 
This handsome Doris may be taken as the type of a group of Dorides, common in 
the Indian Ocean, that have the cloak largely developed and generally coriaceous ; and 
the branchial plumes, six in number, retractile within a cavity with six lobes closing 
over them when withdrawn. This latter character has been employed by Ehrenberg to 
raise them to the rank of a genus, which he calls Actinocyclus. As, however, these 
species agree in all other respects with the characters of Doris, we consider the lobes 
of the branchial aperture not sufficient for generic distinction. The Doris solea of 
Cuvier belongs to this section. 
Doris Evuiot1, n. sp. (Pl. XXVIII. figs. 1, 2.) 
Body oval, depressed. Cloak large, with the upper surface granulated or minutely 
tuberculated, and the edges a little undulated; of a yellowish colour, inclining to 
orange, thickly spotted with umber-brown, the spots larger towards the sides, and the 
