el ee 
yee eT Taee 
17 
the name being evidently employed in this case as a generic one, 
signifying a shell of the kind of the Stamozise, distinguished by a 
collar ; and indeed the description of it seems to be made from a 
specimen of Natica collaria, Lam., which occurs in the Atlantic 
Ocean only. Lamarck, I suppose, intended to call to recollection 
the above denomination of ante-Linnean conchologists by the spe- 
cific name given by him. At the close of the past century Brugiére 
introduced the Conus siamensis, which is admitted generally as a 
distinct species, the geographical range of which, however, extends 
far beyond the limits indicated by the name. ; 
The following are the few Sea-shells from Siam which I observed 
in the collections of Mr. Mouhot :— 
CeriTHIUM optusuM, Lam. Zoology of Samarang, pl. 13. f. 3. 
Natica macutosa, Lam. ; Reeve, Conch. Ie. f. 57. 
CypR#A ARABICA, L. 
MyrILvus SMARAGDINUS, Chemn. 
ARCA NODIFERA, nN. 
Testa ovata, ventricosa, equivalvis, parum inequilateralis, superne 
utrinque obtuse angulata, margine ventrali medio stricto, utrin- 
que rotundato ; coste 21 distantes, anguste, nodose ; inter- 
stitia latiora, concentrice striata ; color albidus, zonis nonnullis 
Suscescentibus ; margo grosse crenatus ; area ligamenti angusta, 
striis divergentibus sculpta ; vertices parvi, remoti. 
Hab. Bankok ; legit Mouhot. 
This species is allied to 4. granosa, Lam. (Reeve, Conch. Icon. 
fig. 15), which is found also in the East Indies: it is distinguished 
from it by the shell being more elongated, and by the ribs, which are 
narrower, and separated by grooves broader than the ribs themselves. 
I have examined three specimens, two of them in the British 
Museum ; they are somewhat different from each other as to the 
outlines of the shell, and I therefore give measurements of them :— 
a. b. ec. 
Bength oo... 3... BY tata Sets cadet, Atl), ra 59 50 52 mill. 
Height from the summits to the ventral margin 42 35 36 ,, 
Diameter from one valve to the other........ 3801322 S2in;s 
CyTHEerREA (MERETRIX) zONARIA, Lam. ; Desh. Cat. Brit. Mus. 
Venerid. p. 38. 
CyTHeREA (MERETRIX) mmpupica, Lam. /.c. p. 36. 
Leg. Sir Richard Schomburgk. 
The posterior area of the shell is in some specimens more purely 
white than the remainder, which is somewhat yellowish, speckled 
with pure white ; in others the shell is bordered by a pinkish-violet 
stripe on the posterior margin. The interior surface of the former 
variety is quite white ; in the other it is provided with a dark-brown 
No. 418.—ProcreEDINGs OF THE ZOOLOGICAL SOCIETY. 
