596 DR. P. P. CARPENTER ON THE PANDORID&. [Nov. 22, 
Animal (as seen through the shell) olive-grey, usually with a red- 
dish tinge about the spire, mottled with dull stone-colour and a few 
black streaky blotches, and about the keel a black marking bordered 
above with silvery grey ; exposed part of body pale greenish white, 
with silvery markings; upper tentacles, and a line extending back- 
wards from each, black ; lower tentacles dusky. 
3. CoNTRIBUTIONS TOWARDS A MONOGRAPH OF THE PANDORID&. 
By Puiurpe P. Carrenter, B.A., Pu.D. 
It is remarkable that, notwithstanding the zeal with which most of 
the old genera have been divided, to meet the wants of modern mala- 
cology, the genus Pandora, Lam., has been left untouched by Dr. 
Gray, Messrs. Adams, and their follower, Chenu. Yet the species 
known to the elder Sowerby present three distinct types of hinge, 
which were well figured by him in his ‘ Conchological Illustrations.’ 
Specimens and even species of Pandora (except of the well-known 
N. Atlantic forms) being very rarely seen in collections, it is pre- 
sumed that naturalists have had but few opportunities of studying 
them. Mr. Cuming having most kindly allowed me to examine the 
hinge of all the species in his collection, it has appeared desirable to 
propose two new genera, and also to group part of the typical species 
under a subgenus. 
It was at one time thought that the presence of an ossicle in the 
cartilage was a family mark of Anatinide, to which Myadora from 
Pandoride, and Tellimya from Kelliade, were consequently removed. 
One of the new genera of Pandorids, however, possesses a well-deve- 
loped ossicle; and a small one is seen even in some species of the 
normal genus. 
The most highly organized structure in the family is found in the 
North American genus Clidiophora, which has both clavicle* and 
ossicle ; the next is the East-Indian group Celodon, which wants 
both clavicle aud ossicle, but possesses a tent-shaped dentition in the 
left valve. The simplest form is the well-known Pandora, which 
has neither clavicle, tent, nor ossicle; but in the subgenus Kennerlia 
the ossicle is present. The genus Myodora is quite distinct, but 
connected with Pandora through Kennerlia. 
Genus CLIDIOPHORAT. 
Testa Pandoriformis, ventraliter expansa; valva dextra tridentata, 
dente postico elongato; valva sinistra sepius bidentata, dente 
antico simplici ; cartilagine ossiculo firmata ; sinu pallii nullo. 
1. Type, CLIDIOPHORA CLAVICULATA, Cpr. (Pandora cl.) P.Z.S. 
1855, p. 228. 
* The word “ clavicle” is used (in default of a better) to denote a linear dental 
process running into the body of the shell, often serving as a support to the car- 
dinal plate, as in Anatina and some species of Placunomia. 
+ Th. cAerdiov, a clavicle; pépw. 
