272 



DISCOVERY REPORTS 



B. South Atlantic. 



Eupteropoda (Thecosomata). 

 Cavolinia longirostris (Lesueur). 

 CavoUnia gibbosa (Rang) in d'Orbigny. 

 Cavolinia inflexa (Lesueur). 

 Cavolinia tridentata (Forskal). 

 Cavolinia tincinata (Rang) in d'Orbigny. 

 Cleodora pyramidata (L.). 

 Cleodora cuspidata (Bosc). 

 Cleodora balanfium, Rang. 

 Cleodora falcata, Pfeffer. 

 Cleodora sulcata (Pfeffer). 

 Hyalocylix (Creseis) striata, Rang. 

 Styliola (Creseis) subula (Quoy and 



Gaimard). 

 Cuvierina coliimnella (Rang). 

 Limacina helicina (Phipps). 

 Limacina balea, Moller. 

 Limacina retroversa (Fleming). 



Limacina helicoides, Jeffreys. 

 Limacina bulimoides, d'Orbigny. 

 Peraclis diversa, Monterosato. 

 Procymhiilia valdiviae, Meisenheimer. 

 Cymbidia peroni, Blainville. 

 Cymbuliopsis intermedia, Tesch. 

 Pterota (Gymnosomata). 



Pneiimoderma atlanticum, Oken. 

 Spofigiobranchaea australis, d'Orbigny. 

 Spongiobranchaea intermedia, A. Pruvot- 



Fol. 

 Pneumodermopsis macrochira, Meisenheimer. 

 Schizobrachium polycotylitm, Meisenheimer. 

 Cliopsis krohni, Troschel. 

 Clione antarctica, E. A. Smith. 

 Thliptodon gegenbatiri, Boas. 

 Thliptodon diaphanus, M^eisenheimer. 



EUPTEROPODA (THECOSOMATA) 



The Eupteropods owe their name to the development of the anterior lateral portions 

 of the foot into wing-like fins. These are placed at the sides of the mouth, which is 

 always on the anterior portion of the ventral surface. The lips of the mouth are covered 

 with vibratile cilia. Nearer the dorsal surface are a pair of tentacles (rhinophores) which 

 are generally unequal in size, the left being often knob-like, while the right, five to 

 twenty times longer, is usually cylindrical, rounded at the end and capable of being 

 withdrawn into a sheath. In Peraclis and in the Cymbuliidae, however, both tentacles 

 are rudimentary and similar in size. The penis is near the tentacles, towards the right. 

 The fins are separated dorsally, but are joined ventrally by a median lobe, which forms 

 the posterior part of the foot and is known as the apron. In the genera Cleodora, Creseis 

 and Cuvierina the fins are bilobed, while in Cavolinia, just near the junction of the fin 

 with the apron, there is a suggestion of another lobe. A large mantle covers the viscera, 

 and the pallial cavity is placed ventrally in the Cavoliniidae and dorsally in the Limacini- 

 dae and Cymbuliidae. Fol (1875) has shown that torsion takes place in the arrangement 

 of the viscera during the development of the Cavoliniidae before the formation of the 

 shell, so that the entire visceral mass, but not the head, the nervous ganglia and penis, is 

 turned from right to left. On account of this the penis and genital duct open on the right 

 in the Limacinidae and on the left in the Cavoliniidae, except the penis which remains 

 on the right side. Cavolinia has also long lateral posterior appendages to the mantle 

 which pass through slits in the shell. 



All Cavoliniids have a " balancer " at the left side of the mantle, and inside the mantle 

 margin, on the ventral side of the body, is a small membranous lobe which constitutes a 



