1864. ] DR. P. P. CARPENTER ON THE PANDORIDE. 599 
Most of the original diagnosis must also be dropped, the parts above 
quoted being all that it is desirable to retain. The present descrip- 
tion is written from notes and drawings made on a careful examina- 
tion of the broken type. The lines of growth show that, so far from 
being ‘‘ cornute,” the species is remarkable for the absence of beak, 
—the margins being more equally rounded even than in P. obtusa, 
which in shape it somewhat resembles. The hinge is almost exactly 
like that of C. edaviculata, jun., but differs in the somewhat greater 
proportionate length of the clavicle, and in the unwonted size and 
sharp pointing of the anterior tooth. The new name has been chosen 
to record this peculiarity, rather than follow the modern custom of 
naming from the author of the mistake. The best naturalists occa- 
sionally err ; but corrections can be made without affixing a false com- 
pliment in perpetuity. 
6. ?CiipiopHora piscors, Sby. (Pandora d.), P. Z. S. 1835, 
p- 99; Sp. Conch. f. 29, 30. 
The type has not been discovered; the figure and diagnosis only 
relate to the outside; and the habitat is not stated. The genus is 
therefore doubtful ; but in shape it resembles the young of (. clavi- 
culata. 
7. ?CxurpropHORA ARcUATA, Sby. (Pandora a.), Sp. Conch. f. 27, 
28; P.Z.S8. 1835, p. 93; Hanl. Rec. Shells, p. 49. 
The worn valves in the Cumingian collection do not allow of a 
confident determination of the genus. 
Genus CaLopon*. 
Testa Pandoriformis : valva sinistra dentibus duobus, cicatricem 
adductoris anticam versus radiantibus, lamina infra cavernosa 
junctis : ossiculo nullo : sinu pallii nullo. 
The shells of this group vary considerably in shape and dentition 
in the different species ; but agree in this, that in the left valve there 
is a kind of tent, formed by a thin laminated roof lying on the top of 
two diverging teeth. It is hard even to guess what is the use of this 
(perhaps unique) structure; especially as its opening is not towards 
the body of the shell, but directly facing the anterior adductor. It 
is seen at once on opening the typical species, which was well figured 
by Sowerby, Sp. Conch. f. 22. In the aberrant forms it might easily 
be overlooked, and a glass is needed to detect it in small specimens ; 
but if it exists, the shell can be supported on a pin thrust into the 
“hollow tooth.”” When more species are known, the group may 
require subdivision, the C. fexuosus especially presenting a marked 
transition to Clidiophora. In that genus the posterior part excels 
in development ; in Ceelodon, the anterior. All the known species 
are from the Eastern seas, but are very seldom seen in collections. 
An enlarged diagnosis of the type species is offered. 
* Th. xotAos, hollow; déovr, tooth. 
