266 MR. P. S. ABRAHAM ON THE [ Mar. 6, 
small, thin, subcrenulate, waved, and transversely striated. Rhino- 
phores apparently short, clavate, laminate and rounded above, 
retractile within small cavities approximated and far forward in posi- 
tion. Branchize 8, small, stout, imperfectly tripinnate, retractile in 
the deep cavity, the margin of which is irregularly denticulate and 
completely contractile. Foot short, broad, truncate in front, not 
extended behind: above the marginal opening for the proboscis are 
two small tentacular lobes. 
Colour of the spirit specimen transparent greyish white, with the 
branchize and the margins of the mouth and of the foot rather darker 
and more opaque. 
Length (in spirit) 21 millims., breadth 14, height 11. 
Hab. St. Vincent (West Indies). 
DoripoPsis MAMMOSA, sp. nov. (Plate XXIX. figs. 20, 21.) 
Body broadly elliptic, convex on the back, very soft and gelatinous. 
Mantle extended all round, semitransparent, and wavy at the border. 
Along each side of the back is a row of 3 large, conical, elongated, 
soft processes, now and then bearing a few tubercles near the base, 
and sometimes rather rugose at the apex; two similar processes are 
situate between the rhinophores; and smaller soft tubercles are 
scattered rather irregularly upon the sides and upon the back. 
Rhinophores clavate and slender, the upper portion diagonally lami- 
nated and with rounded tips; retractile in cavities which have the 
edges raised into short sheaths. Branchie 5, large, ramose, tripin- 
nate, set round the anus in a circle interrupted behind; the anus is 
large, tubular, subpyriform, and is independently retractile within the 
plumes; the general cavity has the wall fleshy and the orifice 
irregularly quinquilobate, and sometimes bearing on the lobes in- 
distinct soft tubercles. Foot broad, truncated in front, rounded 
behind, with the margin, especially at the back, flat and suberenulate. 
There is a very indistinct transverse marginal groove in front, through 
the centre of which passes the short broad proboscis ; and in front 
are two small, free, lateral, flat, rotundate lobes. 
Colour of the spirit specimens yellowish white, darker on the 
margins, on the tubercles, and on the foot; a greyish tinge appears 
on the large processes from within. On the back, between the pro- 
cesses, is a median longitudinal row of three large, very irregular, 
lozenge-shaped black markings, containing within each a subcentral 
large black blotch, as well as one or two short, broad, usually crooked 
black lines; they are often more or less continuous. Two other 
rows, each of 5 or 6 similar but smaller markings, the last two 
always confluent, run, one on each side, from in front of the rhino- 
phores to behind the branchize, outside the lateral rows of large pro- 
cesses. The spaces enclosed in these lozenge-shaped markings are 
always quite smooth. The laminated portion of the rhinophores are 
opaque yellowish brown, the pedicles light and transparent. The 
branchize have the pinnule lineated and tipped with black. 
Length (in spirit) 56 millims., breadth 44, height 16. 
Hab. ? (Obtained during the Antarctic Expedition.) 

