260 MR. P.S. ABRAHAM ON THE [ Mar. 6, 
pointed behind, subprismatic, the dorsal surface flat or but little 
curved ; soft, the sides raised. Mantle small, with the border but 
little extended and not reaching to the foot, or much over the head, 
the edge subcrenulate and upturned in parts, especially in front ; it 
is covered above with minute, soft, flattish tubercles. Rhinophores 
elongate, slender, clavate, pointed, laminated above, inclined laterally, 
and retractile into cavities with the margins raised into very short, 
smooth sheaths. Branchize 6, small, slender, apparently bipinnate, 
the two hinder ones bifid; the anus is short and tubular, and placed 
in front of the interval between the two hindermost plumes; the 
whole system is retractile within a small marginated branchial 
cavity, which is situated very far back. Oral tentacles long, linear, 
and pointed. Mouth subterminal, in the centre of a large rounded 
tubercle. Foot oblong, narrow, truncated in front, free and roundly 
pointed behind, but not reaching beyond the mantle-border. 
Colour of the spirit specimen transparent yellowish white, with 
the viscera showing through the back and side in a purplish patch. 
The mantle-border is marked above with a few greyish pitted spots. 
Length (in spirit) 20 millims., breadth 10. 
Hab. Chilian coast (Chiloe). 
In a small section of the mantle-border no spicules could be dis- 
tinguished. 
Curomoporis? MOLLITA, sp. nov. (Plate XXX. figs. 18, 19.) 
Body oblong, rounded at both ends, not much compressed, soft. 
The mantle is expanded into a short, free, wavy sublobate border, 
rather enlarged posteriorly and over the head; it is nowhere erect. 
Rhinophores apparently short, thick, clavate, with the upper portion 
laminate and pointing backwards; their cavities have the openings 
completely contractile and but barely raised. Branchiee about 27 
in number, irregular, pinnate, some of them divided into two or more 
branches towards the apex ; and the hinder ones are small; they are 
set upon a rhachis, turning inwards behind, which lies in front and 
at the sides of the short tubular anus, and are retractile into a 
cavity with the margin somewhat raised. Mouth subterminal, with- 
out tentacles or veil. Foot oblong, truncated, and with a shallow 
transverse groove in front, rounded, flattened, and extending beyond 
the mantle-border behind. 
Colour of the spirit specimen semitransparent greyish white, 
mottled with opaque white. The roots and midribs of the branchiz 
and the edges of the rhinophore-laminz are opaque white. 
Length (in Bey? 19 millims., breadth 11, height 8. 
Hab. ? 

HeEXABRANCHUS ORBICULARIS, sp.nov. (Plate XXX. figs. 23, 
24.) 
Form depressed, outline nearly circular. Mantle expanded all 
round, except in front, gradually thinning off into a membranous sub- 
crenulate and fimbriate border. Rhinophores small, conical above, 
laminated and recurved, retractile into narrow cavities with slightly 
