The cloaca is divided by transverse circular folds, which project from its inner walls, into three successive chambers.
Trophi virgate exsertile; germary paired; genito-urinary cloaca opening above the neck in the male, subapically in the female.
Gut blind (Paraseison), or opening into cloaca (Seison).
The urino-genital tubes arise from the posterior angles of the pericardium, pass first forwards, then backwards, and unite to open by a common opening into the cloaca below the anus except in A 8 C D FIG.
The mouth is terminal or subterminal; there is a weak sucking pharynx situated behind the brain, and a long intestine lying along the medio-ventral body-cavity; it ends in a cloaca which receives the vasa deferentia in the male.
There are two series of ovaries extending through a large part of the body and accompanied by two uteri; the latter open by two oviducts which debouch into an atrium which also receives the intestine and a single receptaculum seminis, and is continued backward as the cloaca; this opens posteriorly.
The Nematomorpha form an isolated group; at first sight they seem to be connected with the Nematoda, but in reality their only common feature is the tubular genitalia opening into a cloaca, and it seems at present impossible to connect them with the Annelida.
The oviducts are long, usually more or less convoluted tubes which open posteriorly into the cloaca, while their anterior aperture is situated far forward, sometimes close to the root of the lung; their walls secrete a gelatinous substance which invests the ova as they descend.
Copulatory organs are absent, except in the Apoda, in which a portion of the cloaca can be everted and acts as a penis.
Internally they are found to consist of a lamina twisted upon itself, and externally they generally exhibit a tortuous structure, produced, before the cloaca was reached, by the spiral valve of a compressed small intestine (as in skates, sharks and dog-fishes); the surface shows also vascular impressions and corrugations due to the same cause.
The last nerve which contributes to the ischiadic plexus leaves the spinal column in most birds either between the two primary sacral vertebrae, or just below the hindmost of them, and sends a branch to the pubic portion which is composed of post-ischiadic nerves, partly imbedded in the kidneys, and innervates the ventral muscles between the tail and pubis, together with those of the cloaca and copulatory organs.
Cloaca and Genital Organs.
It is significant that the whole type of their cloaca much resembles that of the Crocodilia and Chelonia, in opposition to that of the Lacertilia.
In the great majority of birds it has disappeared completely and the primitive way of everting the cloaca is resorted to.
Gadow, " Remarks on the Cloaca and on the Copulatory Organs of the Amniota."
The sentence was forthwith executed, his body being thrown into the cloaca, where, however, it was found by another pious matron, Lucina, whom Sebastian visited in a dream, directing her to bury him ad Catacombas juxta vestigia apostolorum.
Saginata, showing the generative organs: n., nervous system; ex., longitudinal excretory tubes; tr., transverse vessel; g.p., genital papilla; cl., cloaca; c.p., cirrus pouch; v.d., vas deferens; testes; v., vagina; ov.
5, 6) on the gills of various fresh-water fish; and a large number of genera occur on the skin, cloaca and gills of Elasmobranchs and other marine fish.
It is necessary to use geographical terms in the case of California and the North Pacific, the Caucasus or cloaca gentium of the western hemisphere, where were pocketed forty out of one hundred or more families of native tribes.
In forms living in a tube the intestine turns round and runs forward, the cloaca being placed so as to debouch over the margin of the tube.
The cloaca is often very large; the nephridia and oviducts may open into it, and the eggs lodge there on their way outwards; they are thrown out, as are the faecal masses, by an eversion of the cloaca.
1, bl) which communicates with the cloaca, or directly into the cloaca.
As a rule, the wall of the ovary is continued into a uterine tube opening into the cloaca; but in Philodinaceae this is absent, and the young are free in the body cavity and escape by perforating the cloacal walls.
Insemination takes place either by the introduction of the penis into the cloaca of the female, or by the puncture of the bodywall of the female by the penis, and the injection of the sperm into the body cavity, whence the single spermatozoa must make their way to the eggs.
The di-calcium salt, Ca2H2(P04)2, occurs in a concretionary form in the ureters and cloaca of the sturgeon, and also in guano.