POLYGASTRIA.* These stomachs be subsequently discovered to be variously arranged in different genera, and was consequently induced to make these variations in the construction of the alimen tary apparatus a basis on which to erect a scheme for their further subdivision. This kind of nutritive system of organs he found presented itself under different forms ; in some species the stomachal cavities communicate separately with the oral orifice, so that there is no intestinal tube or passage of intercorn munication between them : to such he has applied the term ANENTERA4 In all others there is a wide intestinal tube in the interior of the body, to the sides of which the numerous alimentary vesicles or reservoirs are appended, terminating by an anal orifice : these have been named from this circumstance ENTERODELA.° The Enterodelous Polygastria are again divi sible :— 1st. Into those in which the intestinal tube is disposed in a circular form in the interior of the body of the animalcule, winding round so that the mouth and anus are contiguous. (CycLoccnte.t) 2nd. Into those in which the intestine tra verses the body of the animalcule, passing along its longitudinal axis, and presenting two orifices completely distinct and opposite to each other ; that which is anterior forming the mouth, the posterior the anus: such are characterized as ORTDOCCELA .t 3rd. Such as have a winding or twisted intestine, which never passes in a direct line through the long axis of the body : these genera are named C AMPY LOCCELA .§ Such a classification, founded entirely on the anatomical arrangement of one set of organs, Ehrenberg acknowledges would be quite con trary to the established rules of zoology, were it not that the external characters of these animalcules are most exactly conformable with the structure of the alimentary canal ; but find ing that the Polygastria are thus resolvable into very natural families, he proceeds to classify them in the following manner :HI Family 1. — MON AD 1 N I ( Monadiclee ).
Polygastric animals, without intestinal canal, without external shell, body uniform, dividing by simple spontaneous fissure into two, but by cross divisions into four or several individuals.
Monas.
Uvella, (1, fig. 1.) Polytoma, (2, fig. 1.) Microglena, (3, fig. 1.) Phacelomonas.
Glenomorum.
Doxococcus.
Chilomonas.
Bodo, (4, fig. 1.) Family 2. — C ItYPTOM 0 N ADI N I D/E. Poly gastric animals, presenting all the characters of the Monadinidw, or at least deprived of the characteristic features of other farnilies, and individually enveloped in a soft or slightly indurated shell.
Cryptomonas.
Ophidomonas.
Porocentrum.
Lagenella, (5, fig. 1.) Cryptoglena.
Trachelomonas.
Family 3.—VOLVOCI N trim. Polygastric ani mals, vvithout intestinal canal, without external appendages, and with the body uniform, similar to the monads, but provided yvith an external en velope or shell, and dividing by complete spon taneous fissure beneath the common envelope into a number of animals which take the form of a polypary. At length the envelope beconies ruptured, and gives passage to the divided animals, which in their turn renew the same process of developement.
GygeS.
Pandorina.
Gonium, (7, 8, fig. 1.) Syncrypta.
- Synura.
liroglena.
Eudorina, (9, 10, fig. 1.) Chlamidomonas.
Splizerosira.
Volvos, (fig. 3.) Family 4.—Vinalomniz. Animals either distinctly or most probably polygastric ; fili form ; without alimentary canal ; without shell or external appendages ; with the uniform body of Monads; associated in filiform chains in consequence of imperfect spontaneous (trans verse) division.
Bacterium.
Vibrio, (1, 2, 3, 4, 5, fig. 5.) Spirochwta.
Spirillum.
Spirodiscus.
Famity 5.—CLOSTERINIDE.. Animals dis tinctly or most probably polygastric, without alimentary canal, and without external appen dages; body uniform, resembling the Crypto monadinidae in their envelope or shell, and dividing, together with their envelope, by spon taneous, transverse fissure, into a bacilliform or fusiform polypary ; provided with moveable papill situated in the aperture of the shell.