REPORT ON THE PTEROPODA. 
67 
the aperture the shell is contracted, but bulges out again towards the partition. The 
embryonic portion is separated from the rest of the shell by a shallow constriction. 
Animal with the aperture of the mantle as large as that of the shell, with fins as in 
Clio ( Styhola ) subula and other species of Clio in the strict sense. The posterior portion 
of the foot is slightly hollowed out in its middle region. 
Adult specimens with the posterior portion intact are very rare. Benson 1 and 
d’Orbigny 2 were the first independently to describe the form of the entire shell, which 
was not known to Rang; when he established the genus “ Cuvieria.” 
Cuvierina is nearly allied to Clio, so much so indeed that Souleyet 3 4 was inclined to 
unite “ Cuvieria ” with “ Cleodora ” as a single division or subgenus. Similarly, 
according to Lesson/ Rang proposed in his unpublished Monograph to unite the above 
forms in a subgenus of “ Cleodora.” 
Among all the species of the genus Clio, Clio ( Styliola ) subula exhibits the closest 
affinity with Cuvierina. Nevertheless, the constriction of the shell behind the mouth, 
the median partition, and the constant truncation, definitely distinguish Cuvierina from 
all the forms of Clio, and warrant its position as a distinct genus. 
But, on the other hand, there is no sufficient reason to establish a distinct family, as 
Gray 5 and the brothers Adams 6 have done. 
It is an entire abuse of nomenclature to apply to this genus the title Triptera, Quoy 
and Gaimard. Nothing could be more uncertain than what Triptera rosea 7 really is, 
as the title is applied to a Pteropod without a shell. 
The genus Cuvierina includes only a single living species. 
* Cuvierina columnella (Rang). 
1824. ? Cleodora obtusa, Quoy et Gaimard, Voyage de rtJranie, Zoologie, p 415, pi. lxvi. 
fig. 5. 
1827. Cuvieria columnella, Rang, Description, de deux nouveaux genres appartenant a la classe 
des Pteropodes, Ann. d. Sci. Nat., ser. 1, t. xiii. p. 323, pi. xlv. 
figs. 1-8. 
1835. Cuvieria oryza, Benson, Corrected characters of the genus Cuvieria and Notice of a second 
species inhabiting the tropical Indian Ocean, Journ. Asiat. Soc. 
Bengal, vol. iv. p. 698. 
1850. Triptera columnella, Gray, Catalogue of the Mollusca in the Collection of the British 
Museum, pt. ii., Pteropoda, p. 23. 
1 Corrected characters of the genus Cuvieria of Rang, &c., Journ. Asiat. Soc. Bengal, vol. iv. p. 698, 1835. 
2 Voyage dans l’Amerique meridionale, t. v. pp. 124, 125, pi. viii. fig. 36. 
3 Voyage de la Bonite, Zoologie, t. ii. p. 203. 
4 Voyage autour du Monde de la Coquill e. 
5 Catalogue of the Mollusca in the Collection of the British Museum, pt. ii., Pteropoda, p. 23. 
6 The Genera of Recent Mollusca, vol. i. p. 54. 
7 Description de cinq genres de Mollusques, &c., Ann. d. Sci. Nat., ser. 1, t. vi. p. / 6, pi. ii. fig. 5, 1825. 
