116 MESSRS. ALDER AND HANCOCK ON 



Genus Doris, LinncBus. 



Body depressed; cloak covering the head and foot. Dorsal tentacles laminated, re- 

 tractile. Oral tentacles variable. Branchiae 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. (PI. 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 httle 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 branchiae 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 

 3^ 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 tuherculata 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 over them when withdrawn.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 ellioti, n. sp. (PI. 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 



