806 BRITISH PALZEOZOIC FOSSILS. [GasTEROPODA. 
LIvoRINA UNDIFERA (JM‘Coy). PI.1. K. fig. 46 and 46 a. 
Ref—td. M°Coy, Ann. Nat. Hist. 2nd Series, Vol. VII. p. 48. 
Sp. Ch.—Turretted, broad, ovate; spire pointed, about three-fourths the length of the body whorl; apical 
angle about 80°; sutures channelled, having a little below them a thick spiral ridge undulated by about eight 
vertical depressions, which cross the whorls of the spire and upper part of the body whorl; below this ridge is 
a wider concave space, bounded by a second thick undulating ridge, forming the most prominent part of the 
whorls: beneath this second ridge, on the body whorl, are about ten very delicate, subequal, spiral threads, dis- 
tinctly separated by concave spaces, about two of which only are visible on the turns of the spire ; entire surface 
crossed by very close, minute, direct lines of growth. Length three lines, proportional length of body whorl {;, 
width slightly more than the length of the body whorl. 
This resembles some of the small oolitic Plewrotomarie, but there is clearly no sinus in the lip, as indicated 
by the direct lines of growth; and the shell is no doubt congeneric with the Z. carinata, from the young of 
which the undulations, &c. distinguish it. 
Position and Locality —In the Aymestry limestone of Mortimer’s Cross, Aymestry, Herefordshire. 
Explanation of Figures.—Pl. 1. K. fig. 46, natural size; fig. 46a, magnified (the undulation of the upper 
keel of the body whorl not sufficiently marked). 
5th Class). CEPHALOPODA (Cuvier). 
Turse are the largest and most highly organised of all the mollusca: they are all carnivorous, and extremely 
voracious, gregarious, nocturnal, marine animals; and instead of being confined, like most Gasteropoda, to 
creeping on the ground, they have various powerful means of locomotion, and many of them live habitually 
in the open sea far from land, which they only approach yearly. The name expresses the most remarkable 
character, of the feet, tentacles, or arms, for creeping and prehension, surrounding the head, which is a 
eranial cartilage enclosing the great cephalic ganglia or brains, and furnished with powerful horny or testa- 
ceous mandibles, the longest below, otherwise like those of a parrot in shape (Zhyncholites), working vertically 
(the jaws of gasterpods, insects, &c., act horizontally), for tearing their prey, and a large fleshy tongue, supplied 
with nerves for taste. The head also bears a pair of very large, highly developed eyes, equalling those of 
fishes in perfection and with a similar fibrous crystalline lens, generally moving freely in an orbital cavity, and 
supplied with nerves, from a special ganglion not existing in any lower mollusca ; there are also more or less 
developed external ears. The body is an oblong, thick, muscular sack, closed posteriorly and open anteriorly, 
varying from spherical to cylindrical, or depressed, and perfectly symmetrical: the head and body are attached 
to each other by ligaments of great strength in the littoral cuttlefishes, but slender in the deep-sea species, in 
which there is a temporary contrivance, called the “‘ apparatus of resistance,” for increasing at any moment the 
strength of the attachment, and affording in its variations a good character for classification. The respiration 
is by gills contained in a large internal cavity, to which the water has access by a valvular opening on each 
side, external to the base of the funnel, and whence it is ejected, by the contraction of the mantle, in jets, 
through a peculiar ventral tube, named the “funnel,” with sufficient force to drive the animal rapidly back- 
wards, forming the chief means of locomotion. Some of the Cephalopoda have external shells, others are 
naked and contain an internal so-called “bone,” giving support to the body, like the bones of the vertebrata, 
but loosely placed in the back of the mantle, without muscular attachment of any sort to the animal. Sexes 
always distinct, and in different individuals. The mouth is followed by a wide crop, opening into a fleshy 
stomach or gizzard, from which extends an intestine, terminating in the base of the funnel or locomotive tube. 
The class is divided into two orders:—1, Tetrabranchiata ; 2, Acetabulifera. 
