Mr. A. Adams on some new Mollusca. 307° 
Fig. 7. Cyathoseris magnifica: a, corallum, two-thirds the natural size; 
b, calice, magnified 2 diameters. 
Fig. 8. Mycedium costatum: a, part of calicular surface, natural size ; 
6, calice, magnified 3 diameters. 
XXXJI.—On some new Genera and Species of Mollusca from the 
Seas of China and Japan. By Arruur Avams, F.LS. &e. 
Atreapy in the ‘ Annals’ I have made known some conchiferous 
Mollusks which I believe to be peculiar types of form with 
which we have hitherto not been acquainted. Such, I conceive, 
is Sarepta among Nuculide, and Cyrilla, the affinities of which 
seem to be with Limopsis. In this communication I have briefly 
characterized two other forms which I am unable to refer to any 
genera already established,—one of which appears to be allied to 
Bucardia, and the other to Montacuta. The new species described 
below are also of great interest on account of their beauty or 
singularity of construction. 
Genus Catiocarpra, A, Adams. 
Testa cordata, tenuis, levis, inflata; umbonibus parvis, subspirali- 
bus, approximatis. Cardo (in valva sinistra) dentibus duobus in- 
gequalibus, cum foveola angusta arcuata interposita, munitus ; dente 
antico valde prominente, in medio angulatim flexo cum fossula antica 
et postica instracto, margine quadricuspidato ; dente postico obliquo, 
arcuato, angusto, elongato, margine denticulis duobus vix elevatis 
instructo ; dentibus lateralibus nullis. Pallii linea simplex ; impres- 
siones musculares semilunares. 
This genus is proposed for the reception of a beautiful shell, 
of which, unfortunately, I possess but a single valve, which in 
general appearance most nearly resembles a Bucardia. The 
surface of the valve is simple, as in B. cor, but it is not covered 
with an epidermis. The complicated nature of what I have 
termed the anterior cardinal tooth, which is furnished with four 
prominent cusps, and is angularly bent on itself in the middle, 
with a triangular pit on each side, together with the absence 
of lateral teeth, will distinguish Callocardia from the Isocardia 
of Lamarck. The genus Anisocardia of M. Munier-Chalmas, 
founded on a fossil shell from the Kimmeridge Clay of Havre, 
appears to bear some resemblance to my proposed genus; but 
in that form the surface of the valves is radiately grooved, the 
anterior muscular scar projects as in Cucullea, and the disposi- 
tion of the hinge-teeth seems to be very different. 
Callocardia guttata, A. Ad. 
C. testa cordata, inflata, levi, nitida, alba, maculis irregularibus 
aurantiacis conspersis pulcherrime guttata, superficie lineis incre- 
