OPISTHOBEANCHIATA FROM THE ABROLHOS ISLANDS. 543 
1843. Duvaucelia Risso, 1826, has to replace Candiella Grray, 1853, as tlie 
valid name for this genus, and thus the oldest generic name in the family 
becomes Duvaucelia, from wliich the family-name is derived. The matter has 
been fully dealt with by Iredale and O'Donoghue (51a, p. 229), and is again 
referred to under the Family Euphuridse (Polyceridse). 
Species Sph^rostoma dakini, sp. nov. (PI. 27. fig. 5 ; PI. 29. figs. 35-40.) 
Body. The body is oblong, limaciform, and like a typical Sphcerostoma. It 
is moderately high, the back flat, and there is a slight pallial extension along 
the edges of the back in the line of the branchial plumes. The dorsum passes 
forward and out as a well-marked, strongly bilobed, oral veil, which bears 
about six or seven dendriform processes on each side of the middle line. The 
short tentacle at each lateral margin of the veil is grooved throughout its 
length upon the ventral side. 
Colour. In the preserved condition some of the specimens were of a dull 
grey colour, and some of the same general colour but plentifulh^ marbled 
with dark brown. Professor Dakin informs me that the living animal is of 
a dirty pinkish colour with brown markings. 
Dimensions. The specimens varied somewhat in size, and the largest 
measured 88 mm. long by 25 mm. wide and 25 mm. high. The lateral 
margins of the oral veil project about 15 mm. 
Head. The head is sub-globose, distinct, but not projecting, and the mouth 
is in the form of a longitudinal cleft. It is completely overhung by the 
bilobed oral veil. 
Foot. The foot is of moderate width and of the same length as the body. 
At the front end it is bilabiate, and posteriorly it passes buck to a blunt point. 
Rldnophores. The rhinophores are retractile within short, stout, cylindrical 
sheaths. This slieath is provided with a funnel-shaped collar with a wavy 
edge and a deep cleft on its antero-lateral side. The clavus bears a ring of 
six simply pinnate plumes, the most anterior is quite small, the most 
posterior is much hirger than the others and is continued upwards as a bluntly 
rounded projecting cylinder. 
Brancliice. The branchiae are in the form of a series of dendritic tufts along 
the side of the dorsum. They are paired and decrease in size as they pass 
backwards; the anterior plumes are attached by a wide long stalk and quite 
distinct from one another, but at the posterior end the stalks are shorter and 
closer together, so that they form a more or less continuous group. About 
ten large distinct plumes are present on each side, and a terminal group 
composed of from 3-5 smaller branchi^. They are of the same colour as the 
body of the animal. 
Radula. As in all the Duvauceliidse the pharyngeal complex is very large 
and the I'aduia very well developed. The total number of rows in the 
radula is 65-67 and the number of teeth in a row — in the Srst row 9 [i. e.. 
