CO N C H O L E PA S .
The foot is truncated, nicked in the middle. The tentacles are short, close together a t their base, with
the eyes on the oute r side o f the ir base. The respiratory canal is short. The operculum is h om y , and p laced
ne a r the back o f th e foot.
The muscles of the foot form a cavity u pon which the liver is la id, so tha t a lamina might be placed
between the liver and the up p e r edge of th e foot as there is in Crepidula.
MONOCEROS.
M o n o c e r o s u n i c o r n e .
Bucc. uuicorne. Brug.
Monoceros crassilabrum. Lam.
Bucc. crassilabrum. Wood. Cat. t. 24. f . 167.—Enc. t. 3 9 6 ./. 2 . ( young).
Mon. glabratum. Lam.
Bucc. Narwal. Brug.
Bucc. dentatum. Wood. Cat. t. 24. f . 169.—Enc. t. 3 9 6 ./. 5.
Purp. Nov0b Hollandiie. B lain. Mon. t. 1 2 ./ . 5.
In h ab . Pacific Ocean.
Varies reddish, purple, and yellow.
M o n o c e r o s m o n o d o n .
Bucc. monodon. Gmel.
Bucc. monoceros. Chemn. x . f . 1469.
Mon. imbricatum. Lam. Var. Mon. breve. Sow. Gen. f .
M o n o c e r o s g r a n d e .
Shell solid, rugose brown, u p p e r whorls with two or three, and last with five or six flat-topped spiral
ridges. Mouth white'; th ro a t ridged, ridges placed in twos and threes. Length 2 } inches.
In h ab . P a c ific Ocean.
M o n o c e r o s p u n c t a t u m .
Shell ovate, fusiform, solid, white, up p e r whorls witli one band, last with three articulated lines o f
black and white spots. T h ro a t purplish, outer lip four or five ridged. Length inches.
In h ab . Pacific Ocean.
M o n o c e r o s l u g u b r e . S o w . G en .f. 3 .
Bucc. deaticulatum and Bucc. amatum. Wood. Cat. Sup. t. 4. / . 11, 12.
Mon. cymatura. Sow. T. C.
Bucc. cymatum. Soland.
In h a b . Pacific Ocean.
M o n o c e r o s m a c u l a t u m .
Bucc. brevidentatum. Gray, Wood, Sup. t. 4 . / . 10.
Purp. cornigera. Blain. Mon. t. 9. / . 10.
In h ab . Pacific Ocean.
T n
‘ ' :
QUO Y IA.
The foot is small, ovate, folded across and crumpled in front, side of the body quite simple. The pro-
boscis short and ringed. The tentacles are slender, conical, far ap a rt a t the b a s e ; the eyes are placed on short
tubercles a t their oute r base. The mantle is simple, with a groove a t the left angle, b u t (in the animal in
spirits) without any appearance o f any d istinc t canal, as is found in the othe r zoophagous M o llu sc a ; b u t in
this character as in others it agrees with P la n a x is . The operculum is h alf ovate, subspiral, o f one and a half
or two whorls; the nucleus is subapical.
This shell only differs from the P lanax e s by having a large groove o n the h inde r pa rt o f the inner lip,
which is continued u p the pilla r, as is found distinctly formed in the young shell, and in the very small size of
the anterior canal. The operculum is said to have a notch behind to fit this groove, b ut I do not find it in
the specimen which 1 have examined, and I am inclined to think th a t it m ust have been an accident in the one
in which it was described.
The genus Pla n a x is has a somewhat similar, b u t n ot q uite so spiral an operculum, and the opercula o f
th ese two genera are more spiral than those of any genera o f zoophagous mollusca. This form of the o perculum
and the absence o f the distinct canal to the front o f the mantle, give some colour to L amarck’s position
o f them amongst the Turbines; and I might be induced to have c ontinued them in this situation if there was not
such a regular gradation of form aud character b etween the P u rp u ra and the P lanax is.
T E R E B R A .
The tentacles of this genus are exceedingly minute, and placed on the uppe r edge o f the inflexed trunk,
and they have no eyes. I n one species from St. Christopher which I have examined, there was no appearance
o f any tentacles, nor eyes ; in another, the tentacles were very small witffdistinct eyes a t the ir lip . The m ale
organ is extremely long, filiform, as long as two whorls o f the shell. The foot is small, folded across when
contracted. The head is rounded. The mantle has a very long slender filiform breathing canal. The operculum
is horny, ovate, nearly as large as the mouth o f the shell, with a rather thickened rib on its inner edge.
Ill n early all the species of this genus the inne r lip is concave and a b so rb ed ; in a few only it is thickened
and elevated.
Buccinum aciculatum and B . p o litum o f L amarck must be moved to this genus.
EBU RN A.
The tentacles are triangular, rather short, separate a t the b a s e ; the eyes are small, ne a r the oute r base of
the tentacles. The male organ is rather sm a ll; foot longitudinally and transversely folded when contracted.
The operculum is horny, acute m front, nearly as large as the mouth, concentrically striated, with the nucleus
in front, and the inner ridge is thickened internally. (E . spirata).
BU L L IA . ■ 9 -
The animal o t this genus is very peculiar tor Ihe very large size o f its foot, which is much larger than
the sh e ll; when contracted the foot is folded together, and is capable o f being withdrawn into the cavity
o f the shell. They have no eyes ; and the tentacles are longand subulate, and placed on the side of the head