MOLLUSCA. 775 
Sp. Tiedemannia neapolitana V. BENED., proboscis slender, pinne with 
white and yellow spots at the margin. Length 2 or 3”. See GmEGENBAUR 
1. 1. s. §4—68 for the anatomy and development, gen. char. p. 212. ] 
Family II. Cloidea. Naked Pteropods, with head distinct. 
[The small foot on the ventral surface never connate with pinne. 
GEGENB. | 
Pneumodermon Cuv. Two small pinne at the sides of neck 
with an intermediate grooved conical appendage. Mouth with 
numerous pediculated retractile suckers. 
Sp. Pnewmodermon Peronit Cuv., Ann. du Mus. tv. Pl. 59 B, Buatnv. Malac. 
Pl. 46, fig. 4; this animal was discovered in the Atlantic Ocean by P&Ron, 
and appears to differ from that figured by Quoy and GarMARD in the 
voyage of the Astrolabe (copied in Cuv. R. ani., éd. ill., Mollusg. Pl. 17, 
fig. 2), where the suckers stand like branches on two pedicles. Pnewmo- 
dermon violaceum D’ORBIGNY has a greater resemblance to it, the anatomy 
of which has been given by V. BENEDEN with figures in MUELLER’S Archiv, 
1838, pp. 296—304, Pl. 1x. x. There is still uncertainty respecting the 
respiratory organs, and the name PNEUMODERMON rests perhaps on a 
mistake. [Pn. ciliatwm GEGENB., see the anatomy, &c. 1. 1. s. 74—100. 
The folds of the integument, here absent, which serve for respiration, are 
described in Pn. violaceum and P. Mediterraneum, pp. 85, 86. | 
Spongiobranchea D’Ors. (Is this genus distinct from the pre- 
ceding ?) 
D’Orsieny Voyage dans ?Amér. mérid. (transferred to OKEN’s Jsis, 
1839, s. 498, Tab. I. 1X. figs. 1—9). 
Clio L., Clione Pauu., Escuricut. Body oblong, acuminate 
posteriorly. Head distinct from body by stricture, covered by a 
bilobed hood, crowned by six conical appendages, and two retractile 
conical tentacles. Two oval pinne at the sides of neck. ‘Two 
black points (eyes) in the back of neck. Two genital apertures at 
the right of the ventral side, the anterior in front of pinne for 
the exit of a very large penis, the posterior behind the pinne 
for the oviduct. Anus behind these orifices, more in the middle. 
Sp. Clio borealis GmEw., Clione borealis Pauu., Spic. Zool. x. Tab. 1. figs. 
18, 19, Cuvier Ann. du Mus. 1. pp. 242—250, Pl. 17, D. F. Escuricut 
Kongl. Danske Vetensk. Selskabs Afhandl. Kj6benhayn, 1838 (published 
separately in German, Anatom. Untersuchungen ti. d. Cl. boreal. Kopen- 
hagen, 1838, 4to.) The six conical arms of the head are beset with spots, 
microscopic suckers. This animal (Whale-bait), Clio limacina Puipps, 
lives with Clio helicina principally in the neighbourhood of Greenland and 
Spitzbergen, and forms the chief food of northern whales, although scarcely 
1” long. Cuvier regarded the fin-like appendages as respiratory organs, but 
