CYMBIUM. 
Prats XX. 
Species 12. (Fig. a, 6, c, d, Mus. Cuming.) 
CyMBiuM PorcInuM. Cymb. testé cylindraceo-ovatd, sub- 
recté, flavescente, spirdé brevissimd, apice mamillari, 
parum exserto, anfractibus superné rudé acute dilatato- 
productis, circa apicem laté canaliculatis ; columella 
bi-triplicatéa. 
Tur nog Cymsium. Shell cylindrically ovate, rather 
straight, yellowish, spire very short, apex mamillary, 
but little exserted, whorls rudely sharply dilately pro- 
duced round the upper part, broadly channelled round 
the apex; columella two- to three-plaited. 
Voluta porcina, Lamarck, Anim. sans vert. vol. x. p. 383. 
Voluta cymbium, pars, Linnreus. 
Cymbium porcinum, Menke. 
Cymba porcina, Broderip. 
Fetus proboscidalis, pars, Gray. 
Hab. West Africa. 
Conchologists are divided in opinion as to whether this 
is a distinct species, or merely a variety or young of the 
preceding. Mr. Lowe, the latest authority on the subject, 
says (Pro. Linn. Soc. 1860, p. 193), ‘‘ Dr. Gray unites 
C. proboscidale with C. porcinum, of which it may possibly 
prove, indeed, to be only a large, mature or full-developed 
state or form; but further observations of the shells and 
animals conjointly seem still requisite to justify such com- 
binations.” In the face of this remark, coming from so 
experienced an observer as Mr. Lowe, I have kept the 
species distinct, but I must confess my inability to make 
out more than one in an early stage of growth. All the 
very young and more advanced specimens, of which there 
are many in collections, have the straight form and more 
dilated corona-ledge of C. porcina, and it is not improbable 
therefore that the attenuated contraction of the ends of the 
shell of C. proboscidale, like the callous overlaying and im- 
mersion of the apex, may be the result of age. Still, spe- 
cimens of C. proboscidale are known in a state which is 
apparently scarcely mature, and all have an additional 
winding plait at the base of the columella. 
Dr. Gray calls in question a remark made by Mr. Adams 
in his ‘ Genera,’ that this section of the Cyméia have a de- 
ciduous nucleus. Myr. Cuming certainly possesses speci- 
mens of C. porcinum in which the nucleus, of a rude swol- 
len growth, such as represented in Fig. 12 c, has been cast, 
still leaving a mamillary apex; and he possesses also a 
specimen of a cast nucleus, with the base almost walled 
in, as it would be prior to being cast off. 
February, 1861. 
