REPORT ON THE PTEROPODA. 
61 
♦ *9. Clio balantium (Rang). 
1829. Balantium recurvum, Anonymous (Children, fide Gray), Journ. Roy. Inst., vol. xv. p. 220, 
pi. vii. fig. 107. 
1834. Cleodora balantium, Rang, Magasin de Zoologie, 1834, pi. xliv. 
1836. Hyalsea balantium, d’Orbigny, Voyage dans lAmerique meridionale, t. v. p. 116, pi. viii. 
figs. 1-4. 
1837. Balantium bicarinatum , Benson, Notice on Balantium, a Genus of the Pteropodous 
Mollusca, Journ. Asiat. Soc. Bengal, vol. vi. p. 151. 
1852. Cleodora infiata, Souleyet, Voyage de la Bonite, Zoologie, t. ii. p. 188, pi. vii. figs. 17-19 
(young). 
For description and figures, I refer to Souleyet, Voyage de la Bonite, Zoologie, t. ii. 
p. 186, pi. vii. figs. 11-16. 
Habitat. — Atlantic Ocean; intertropical (21° 30' N. to 19° 30' S., Boas); 44° N. 
(Atlantic?) (Pfeffer); toward 40' X., coast of America (Verrill, fragments). 1 
Indian Ocean; exclusively in the southern portion, 33° S. towards Africa (Boas), 
towards Australia (Pfeffer), Islands of St. Paul and Amsterdam (Benson). 
Challenger Specimens. — Living. 
Station 216 a, February 16, 1875; north of New Guinea; lat. 2° 56' N., 
long. 134° 11' E. (young). 
# 10. Clio chaptali (Souleyet) (PI. II. fig. 7). 
1852. Cleodora chaptali, Souleyet, Voyage de la Bonite, Zoologie, p. 183, pi. vii. figs. 1-5. 
The above form appears to be a distinct species, but very strictly localised, for it has 
not been reobserved since its discovery by Souleyet. I only know a single adult specimen 
(dry shell), which is deposited in the British Museum. 
Characters and Description. — Shell somewhat bulging, with its apex recurved 
dorsally, with its lateral edges uniformly and markedly diverging, in contrast to Clio 
balantium, where they describe a sigmoid curve. The lateral keels are sharp and not 
hollow-edged, as they are in Clio balantium ; they run parallel to the axis of the body, 
and are not at all turned ventrally ; this admits of the ventral surface being as bulging 
as the dorsal. The latter bears five longitudinal ribs, instead of three as in Clio 
balantium. The middle of the lips hardly projects anteriorly. The embryonic shell is 
separated from the rest by a well-marked constriction, in front of which the shell 
broadens out again. The embryonic portion, however, in contrast to that of Clio 
balantium, does not enlarge behind the constriction, and is terminated posteriorly by a 
much -pointed apex (PI. II. fig. 7). 
The animal, according to Souleyet, very closely resembles Clio balantium. 
1 Catalogue of the Marine Mollusca added to the fauna of New England during the past ten years, Trans. Connect 
Acad., vol. v. p. 557. 
