20 Mr. A. Adams on new Mollusca from Japan. | 
IV.—Mollusca Japonica: New Species of Odostomia. 
By Artuur Apams, F.L.S., &c. 
Tue genus Odostomia, as at present constituted, comprises a 
very incongruous assemblage. Many species appear to belong 
to Parthenia, such as O. terebellum and O. Humboldtii, Phil. O. 
Achates, Gould, is an Obeliscus, as is also, I believe, O. lamellata, 
Carp. The British forms also require supervision ; and this is the 
more necessary in a family where the species are already so 
numerous and of such small dimensions. In the work by my 
brother and myself, which is merely a rough sketch of the mol- 
luscous subkingdom, every genus of small shells could not be 
minutely analysed; but when complete monographs of all the 
genera shall have been made by competent persons, some degree of 
exactness will be given to the smaller divisions, and the study of 
species be thus facilitated. In the meantime, I offer descriptions 
of fourteen species of true Odostomie from a sea whence not a 
single species has hitherto been obtained by naturalists. 
1. Odostomia oblonga, A. Adams. 
O. testa ovoidea, utrinque acuminata, alba, solida, imperforata; an- 
fractibus normalibus 4, planatis, ultimo magno ovato; apertura 
oblonga, antice .producta et acuminata; plica parietali obliqua, 
valida; labro arcuato, subincrassato. 
Hab. Korea Strait, near Mino-Sima; 63 fathoms. 
2. Odostomia hyalina, A. Adams. 
O. testa ovato-conica, tenui, subdiaphana, alba; anfractibus norma- 
libus 5, planulatis, ultimo ad peripheriam subangulato; suturis 
acute exaratis; apertura oblongo-ovali, antice subproducta ; plica 
parietali transversa, valida; labro in medio subangulato. 
Hab. Mino-Sima; 63 fathoms. 
3. Odostomia elata, A. Adams. 
O. testa elongato-conica, spira acuminata, alba, nitida, solida; an- 
fractibus normalibus 5, planatis ; suturis exaratis ; anfractu ultimo 
ad peripheriam subangulato; apertura ovata; plica parietali 
obliqua; labro in medio subangulato. 
Hab. Mino-Sima; 63 fathoms. 
4. Odostomia scalina, A. Adams. 
O. testa elongato-conoidea, subturrita, spira elata, alba, rimata, 
tenui; anfractibus normalibus 5, convexis, ultimo rotundato ; 
suturis impressis ; apertura oblonga; plica parietali parva, trans- 
versa; labro simplici, acuto. 
Hab. Mino-Sima; 60 fathoms. 
