S.A, NAT., AX»L. XIV. 
May, 19.33. />>' Bernard C. Colton and F. K. Godfrey. 
9l 
insides (: — inner sides) of parapodia very dark; posterior wings 
(M mantle short, without a filament. Shell unknown. Australia. 
(CloLild).” 
CAVOLINIDAE. 
Sliell external, calcareous; inopcrculated, bilaterally sym- 
metrical, not rolled up in a spiral, but at its apex often dorsally 
recurved. The shell has a variable form, which may always be 
referred to as a hollow cone, more or less modified, flattened 
dorso-vcntrally or circular in section; apex quite straight, re- 
curved, or truncated; mouth broad or narrow; ribs axial or 
spiral. Initial portion of the shell, generally distinct from the 
rest, represents the protoconch. Distribution — High seas, in all 
latitudes, very numerous in the tropics, floating constantly in 
the water by means of the lateral fins. Fossil — Palaeozoic. Ani- 
mal, entirely retractile within the shell, with pallial cavity ven- 
tral, columellar muscle dorsal, anus situated on the left; the lorm 
of the fins and of the posterior lobe of the foot varies considerably. 
Cavoiina Abildgaard 1791. Generally horny-brown colour, 
esj'ccially characterized by its much contracted aperture, which 
is, however, very broaci transversely; the lateral portions of this 
aperture, which are narrower than the middle part, are almost 
separated from it b}' a more or less developed tooth arising 
from the ventral lip and luting into a dorsal depression; dorsal 
lip, which is longer than the ventral, is always more or less 
ventrally recurved; ventral lip, muclt recurved dorsally, is con- 
stricted a little in front of the aperture and then reflected ven- 
trally; ventral surface always bulging. The special form of 
Cavolina depends on the fact that the sides of the shell diverge 
abruptly outwards, so that the lips appear much prolonged an- 
teriorl}-; the sides of the shell are often prolonged into a more 
or less projecting point. The cmbr)’onic shell is not separated 
by a distinct constriction, d'ype — C. nutans Abildgaard. 
C. inflexa l..csueur 1813 {Ilyalacci) . *'d’he Curved Cavo- 
lina.*’ iflongated, conical, ccnnpresscd on each side, elongated 
posteriorly, terminated by a recurved point, laterally armed with 
a short point; mouth ovately transverse, laterally deeply cleft. 
Height 6, diam. 4 mm. Neptune Islands, 104 fathoms. 'Fwo 
examples. j^(.)calities — Atlantic. Pacific and Indian Ocean. 
The distinguishing feature of this species appears to be the 
up[-'cr lip directed straight forwards. 
C. telemus J^inne 1758 {Monoculiis) (— tridentata 
Pelseneer 1888). Globular, thin, pellucid, yellowish, transverse 
striations ver\' fine; hinder central process short, terminal tooth 
longer than the lateral ones. Height 15, diam. 12 mm. Cape 
Jaffa 300 fathoms, Beachport 110-150 fathoms. Neptune Islands 
