Part of the membranous roof between the supra-occipital and parietal bones frequently remains unossified and presents in the macerated skull a pair of fontanelles.
The cottontails, or wood-rabbits, of North and South America are regarded as forming a genus, Sylvilagus, by themselves, which includes the Brazilian and Paraguay hares, and appears to be chiefly distinguished by a certain feature in the parietal region of the skull.
C, The one-celled ovary cut a, The anther, con transversely, having three taining pollen parietal placentas.
Parietal bones separated by the supraoccipital; prootic and exoccipital separated by the enlarged opisthotic. Pectoral arch suspended from the skull; no mesocoracoid arch.
In the Gymnolaemata protrusion is effected by the contraction of the parietal muscles, which pass freely across the body-cavity from one part of the body-wall to another.
In the branching Ctenostomes the entire body-wall is flexible, so that the contraction of a parietal muscle acts equally on the two points with which it is connected.
The parietal muscles (p.m.), which pass from the vertical walls to the frontal wall, thus act by depressing the latter and so exerting a pressure on the fluid of the bodycavity.
In Cheilostomata with a rigid frontal wall A, of Membranipora; B, of an Jullien showed that proimmature zooecium of Cribrilina trusion and retraction were p.m., Parietal muscles.
(iii.) In Umbonula of Cribrilina, showing the frontal membrane and parietal the entrance to the muscles of the young zooecium are like compensation - .sac on those of Membranipora, but they become the proximal side of the covered by the growth, from the proximal operculum (op).
With few exceptions they have amphicoelous vertebrae, the parietal bones remain separate and they have no eyelids, with very few exceptions.
Procoelous vertebrae; ventral portions of the clavicles not dilated; parietal bones fused into one.
The ovary of passionflowers is one-celled with three parietal placentas, and bears at the top three styles, each capped by a large button-like stigma.
Dogs were first classified into three groups: - (i) Those having the head more or less elongated, and the parietal bones of the skull widest at the base and gradually approaching towards each other as they ascend, the condyles of the lower jaw being on the same line with the upper molar teeth.
B, Parietal band.
According to some writers (Leuckart) they are derived from undifferentiated blastomeres, other authorities (Thomas, Biehringer, Heckert) trace them to the parietal cells of the larva.
P.m., Parietal muscles.
The parietal muscles are usually reduced to.
X P11,1x, premaxilla; Mx, maxilla; Ma, malar; Fr, frontal; L, lachrymal; Pa, parietal; Na, nasal; Sq, squamosal; Ty, tympanic; ExO, exoccipital; AS, alisphenoid; OS, orbito-sphenoid; Per, mastoid bulla.
B, The spiral archicarp (as), w, Parietal cells.
The organ seems also to receive many fibres from the parietal region of the cerebral hemisphere.
Since this must have, on our theory, enclosed the parietal canal from the anterior coelom, it is possible that the genital products were developed from the lining cells of that cavity, and that the genital pore was nothing but its original pore not yet united with that from the water-sac. The concrescence of these pores can be traced in other cystids; but as the genital organs became affected by radial symmetry the original function of the duct was lost, and the reproductive elements escaped to the exterior in another way.
A general nerve-plexus probably exists over considerable parts of the skin, and there are special nervous concentrations in the region of the epistome and along a double crescent (N) which follows the parietal attachment of the coelomic septum.
The flowers spring from, or are enclosed in, a spathe, and are unisexual and regular, with generally a calyx and corolla, each of three members; the stamens are in whorls of three, the inner whorls are often barren; the two to fifteen carpels form an inferior ovary containing generally numerous ovules on often large, produced, parietal placentas.
A parietal foramen; scales or bony scutes frequently present, especially on the ventral region, which is further protected by three large bony plates - interclavicle and clavicles, the latter in addition to cleithra.
The pineal foramen, in the parietal bones, is as constantly present as it is absent in the other orders.
When there is a single ovule, with its axis vertical, it may be attached to the placenta at the base of the ovary (basal placenta), and is then erect, as in Polygonaceae and Compositae; or it may be inserted a little above the base, on a parietal placenta, with its apex upwards, and then is ascending, as in Parietaria.
It may hang from an apicilar placenta at the summit of the ovary, its apex being directed downwards, and is inverted or pendulous, as in Hippuris vulgaris; or from a parietal placenta near the summit, and then is suspended, as in Daphne Mezereum, Polygalaceae and Euphorbiaceae.
The placentas are parietal, and the ovules appear sessile on the walls of the ovary.
Pmt, p m 3, and pm', The three Pa, Parietal bone.