CYMBIUM. 
Pratt XIV. 
Species 7. (Mus. nost.) 
CymMBiuM DIADEMa. Cymb. testdé ovata vel suboblongo- 
ovatd, utringue attenuata, albidd vel aurantio-lacted, 
cinnamomeo vel ustulato-brunneo plus minus tinctd et 
undato-strigatd, strigis bifasciatim nebulatis, spird 
subimmersd, anfractibus superné obtuse angulatis, squa- 
mis subdistantibus, sepe elongatis, conspicue coronatis ; 
columellé validé triplicatd. 
THE DIADEM CymBiuM. Shell ovate or rather oblong- 
ovate, attenuated at each end, whitish or orange- 
cream, more or less stained and wave-streaked with 
cinnamon or burnt brown, streaks clouding in two 
bands, spire rather immersed, whorls obtusely angled 
round the upper part, conspicuously coronated with 
rather distant, often elongated spines; columella 
strongly three-plaited. 
Voluta diadema, Lamarck, Anim. sans vert. vol. vi. p. 375. 
Voluta armata, Lamarck. 
Hab. Kastern Seas. 
This is the most variable of all the Cyméia; and the 
more slender forms of the species, with long spines, have 
been separated under the name of Voluta armata, La- 
marck (Melo armatus, Broderip, Cymbium armatum, Gray), 
from the more square-built and stoutly ventricose speci- 
mens with shorter spines. But these variations, depend- 
ing on the laws of correlation of growth, are not accom- 
panied by a separate system of specific characters, as in 
O. ducale and Georgineg. It is perfectly impossible to 
draw a line between them. ‘The fine specimen represented 
in the accompanying Plate is about intermediate between 
them, leaning rather to the armatum form of the spe- 
cies. In more slenderly convoluted specimens the spire 
is more sunk and the corona of scales more conspicuously 
elongated. 
February, 1861. 
