96 
THE VOYAGE OF H.M.S. CHALLENGER. 
and demand the establishment of a new division which I propose to call Cymbu- 
liopsis. 
The only way of distributing the different species of Cymbuliidse seems to me to be 
as follows : — 
1. Gleba; proboscis free, fin with a continuous margin, shell flattened, with almost 
no cavity. 
2. Cymbuliopsis ; proboscis free, fin with a continuous margin, shell in form of a 
slipper, with a very large cavity. 
3. Cymbulia; proboscis fixed throughout its entire length, fin with a ventral lobe, 
shell thick, with a reduced cavity. 
The genus Cymbulia will include (1) Cymbulia peroni, de Blainville, (2) Cymbulia 
parvidentata, n. sp., (3) a form of which a specimen without shell was collected by the 
Challenger in the Western Pacific Ocean, and very probably also the Cymbulia of the 
Indian Ocean figured by Macdonald. 
The genus Cymbuliopsis will include (l) Cymbulia ovata, Quoy and Gaimard, and 
(2) Cymbulia calceola, Yerrill. 
Finally, the genus Gleba will include (1) Gleba cor data, Forsk&l, (2) Tiedemannia 
chrysosticta, Krohn, and (3) Corolla spectabilis, Dali. 
Cymbulia, 1 Peron and Lesueur. 
1810. Cymbulia, Peron et Lesueur, Histoire de la famille des Mollusques Pteropodes, Ann. Mus. 
Hist. Nat. Paris, t. xv. p. 66. 
Characters and Description. — The “ shell ” or deutoconch, described as cartilaginous 
or gelatinous, is elongated in a dorso-ventral direction, and has a moderately elongated 
cavity and a pointed dorsal extremity. The external surface is covered with tubercles 
arranged in rows parallel to the main axis, the dorsal extremity is always dilated and 
projects more or less markedly. 
The animal has a natatory disc of considerable breadth, and a ventral lobe on the foot. 
The cephalic portion is reflected on the dorsal margin of the fin, but is fixed throughout 
its length, and constricted towards its distal extremity. A radula and jaws. 2 
The orientation of Cymbulia, and indeed of all the species of Cymbuliidae, has been 
generally misunderstood, especially in general works on Mollusca. First of all, in regard 
to the position of the animal within the shell there has been a difference of opinion 
somewhat analogous to that ancient discussion in regard to Nautilus. 
1 Corruption of Cymbula, slipper. 
2 Woodward, in his Manual of the Mollusca (1856), notes two stomachal plates, while in 1839 van Beneden 
recognised four, and this any one might verify. Nevertheless the manuals of conchology have continued to copy from 
Woodward, and mention only two plates, as for example in the Structural and Systematic Conchology of Try on — a 
compilation destitute of scientific value. 
