A, Lateral region of the cephalic plate to which the first pair of appendages are articulated.
- Anterior portion of the same and opening on the right Limpet, with the overhanging cephalic shoulder, so to speak, of hood removed.
Four pairs of appendages besides these are seen to belong to the cephalic tergum.
Cephalic or first prosomatic 2, Second do.
B, Cephalic tentacle.
Dv, Velar area or cephalic dome.
M, Mantle-flap reflected over the 0, Posterior cephalic tentacles.
O, The cephalic tentacles.
A, mouth; b, cephalic tentacle; h, gill (ctenidium).
(Lankester.) Anterior cephalic tentacle.
Posterior cephalic tentacle; and b, the eyes.
46, B), possibly a continuation of the epipodia; b, b', cephalic tentacles.
A, b, Posterior and anterior cephalic tentacles.
A, The cephalic hood.
B, Cephalic tentacles.
A, Nerve to superior cephalic tentacle.
B, Nerves to inferior cephalic tentacles.
Cephalic shield continuous with neck; twelve to fourteen stomachal plates; a posterior pallial filament passing through a notch in shell.
Foot very broad; cephalic shield with four tentacles; shell external, thin, without prominent spire.
Cephalic shield broad, thick and simple; shell wholly internal, thin, spire much reduced, aperture very large.
Cephalic shield ending posteriorly in a median point; shell internal, largely membranous; no radula or stomachal plates.
Cephalic shield pointed behind; shell internal, chiefly membranous, with calcified nucleus, nautiloid; parapodia forming fins.
Cephalic shield continuous with dorsal integument; no shell; ctenidium projecting from mantle cavity.
B, Pair of cephalic tentacles.
1, Cephalic tentacles.
Karl Semper has shown that these slugs have, in addition to the usual pair of cephalic eyes, a number of eyes developed upon the dorsal integument.
Curiously enough, however, they differ from the cephalic Molluscan eye in the fact that, as in the vertebrate eye, the filaments of the optic nerve penetrate the retina, and are connected with the re surfaces of the nerve-end cells nearer the lens instead of with the opposite end.
Hickson and others, that in the bivalves Pecten and Spondylus, which also have eyes upon the mantle quite distinct from typical cephalic eyes, there is the same relationship as in Oncidiidae of the optic nerve to the retinal cells.
The brain innervates the eyes and feelers, and must be regarded as a " syncerebrum " representing the ganglia of the three foremost limb-bearing somites united with the primitive cephalic lobes.
The development of these organs, which in the Protonemertine are but grooves in the epidermis, not far removed from the similar cephalic slits of many Turbellaria, reaches its height in Drepanophorus.
They are the head slits cephalic fissures, " Kopfspalten ") so characteristic of this subdivision (figs.
That any partial fusion of originally distinct chitinous plates takes place in the cephalic shield of Trilobites, comparable to the partial fusion of bony pieces by suture in Vertebrata, is a suggestion contrary to fact.
Cephalic index >>
In the Orthorrhapha, in the pupae of which the appendages of the perfect insect are usually visible, the pupa-case generally splits in a straight line down the back near the cephalic end; in front of this longitudinal cleft there may be a small transverse one, the two together forming a T-shaped fissure.
Anterior area of the mantle-skirt over-hanging the head (cephalic hood).
Below the surface these walls are excavated with blood-vessels, so that the sac is practically a series of blood-vessels covered with renal epithelium, and forming 6 Cephalic tentacle.
They are found one on each cephalic tentacle, and are simply minute open pits or depressions of the epidermis, the epidermic cells lining them being pigmented and connected with nerves (compare fig.
An epipodial ridge on each side of the foot and cephalic expansions between the tentacles often present.
T, Cephalic tentacle.
(Lankester.) a, Cephalic tentacle.
The head is seen in front resting on the foot and carrying a median non-retractile snout or rostrum, and a pair of cephalic tentacles at the base of each of which is an eye.
I, Under surface of the mantle c, Cephalic eye.
Skirt forming the roof of the d, Cephalic tentacle.
D, Proand meso-podium; to the right b, Cephalic tentacles.
N, Dorsal surface overhung by Cephalic tentacles.
The Heteropoda are further remarkable for the high development of their cephalic eyes, and for the typical character of their osphradium (Spengel's olfactory organ).
Oc, Cephalic eye.
Shell flattened; no cephalic tentacles.
Shell depressed, with rounded aperture; cephalic tentacles long.
Shell spiral; four cephalic tentacles; eyes absent; two pedal appendages.
34.-Female Janthina, with egg-float (a) attached to the foot; b, egg-capsules; c, ctenidium (gill-plume); d, cephalic tentacles.
B, Cephalic tentacles.
The detorted visceral commissure shows a tendency to the concentration of all its elements round the oesophagus, so that except in the Bullomorpha and in Aplysia the whole nervous system is aggregated in the cephalic region, either dorsally or ventrally.
It carries two pairs of cephalic tentacles and a pair of sessile eyes.
Cephalic shield bifid posteriorly; margins of foot slightly developed; genital duct diaulic; visceral cornmissure streptoneur ous; shell thick, with prominent spire and elongated aperture; a horny operculum.
Cephalic disk enlarged anteriorly, forming an open tube posteriorly; shell external, thick, with p:ominent spire; no operculum.
Cephalic shield short, truncated posteriorly; eyes deeply embedded; three calcareous stomachal plates; shell external, with reduced spire.
A, Cephalic tentacle.
B, Cephalic tentacles.
(After Cuvier.) t, Anterior cephalic tentacles.