Aristotle's History of Animals / In Ten Books

by Aristotle

10. In the larger cochli a long white passage, contained in a membrane, and in colour resembling the upper mastoid appendages, is joined from the stomach to the œsophagus, and it is divided into segments like the ovum of the carabus, except that it is white, while the other is red. It has neither exit nor passage, but it is contained in a thin membrane, which has a narrow cavity. From the intestine black and rough bodies descend continuously, like those in the tortoise, but they are less black.

11. Both these and white bodies occur in the marine cochli, but they are less in the smaller kinds. The univalves and bivalves are in some respects like these, and in others they are different, for they have a head, horns, and mouth, and something like a tongue, though in smaller species these are inconspicuous from their minute size, and they are not discernible when the animals are dead or at rest. They all contain the mecon, but not in the same position, nor of the same size, nor equally conspicuous. In the lepas it is in the bottom of the shell, in the bivalves near the hinge.

12. They all have hair-like appendages placed in a circle, and so have the pectens, and that which is called the ovarium in those that have it; where it is possessed, it is placed in a circle on the other side of the circumference, like the white portion in the cochli, for this is alike in all. All these parts, as I have said, are conspicuous in the larger kinds, but in smaller not at all, or scarcely so, wherefore they are most conspicuous in the larger pectens, and these have one valve flat like an operculum.

13. The anus is placed in the side in some of these creatures, for this is where the excrement passes out. The mecon, as I have said, is a superfluous part enclosed in a thin membrane in all of them; that which is called the ovarium has no passage in any of them, but it swells out in the flesh. This is not placed upon the intestine, for the ovarium is on the right side and the intestine on the left; the anus is the same as in others; but in the wild patella, as some persons call it, or the sea-ear (haliotis), as it is named by others, the excrement passes out below the shell, for the shell is perforated. The stomach also is distinct behind the mouth, and so is the ovarium in this animal. The position of all these parts may be seen in dissections.

14. The creature called carcinium[131] resembles both the malacostraca and the testacea, for this in its nature is similar to the animals that are like carabi, and it is born naked (not covered with a shell). But because it makes its way into a shell, and lives in it, it resembles the testacea, and for these reasons it partakes of the character of both classes. Its shape, to speak plainly, is that of a spider, except that the lower part of the head and thorax is larger.

15. It has two thin red horns, and two large eyes below these, not within nor turned on one side, like those of the crab, but straight forwards. Below these is the mouth, and round it many hair-like appendages; next to these, two divided feet with which it seizes its prey, and two besides these on each side, and a third pair smaller. Below the thorax the whole creature is soft, and when laid open is yellow within.

16. From the mouth is a passage as far as the stomach; but the anus is indistinct; the feet and the thorax are hard, but less so than those of the cancri; it is not united with the shell like the purpura and ceryx, but is easily liberated from it. The individuals which inhabit the shells of the strombus are longer than those in the shells of the nerita.

17. The kind which inhabits the nerita is different, though very like in other respects, for the right divided foot is small, and the left one large, and it walks more upon this than the other; and a similar animal is found in the conchæ, though they are united to their shells very firmly; this animal is called cyllarus.[132] The nerita has a smooth, large, round shell, in form resembling that of the ceryx, but the mecon is not black, but red; it is strongly united in the middle.

18. In fine weather they seek their food at liberty, and if a storm arises, the carcinia hide themselves under a stone, and the neritæ attach themselves to it like the patella, the hæmorrhois, and all that class, for they become attached to the rock, where they close their operculum, for this resembles a lid; for that part which is in both sides in the bivalves is joined to one side in the turbinated shells: the interior is fleshy, and in this the mouth is placed.

19. The nature of the hæmorrhois, the purpura, and all such animals is the same. But those which have the left foot greater are not found in the shells of the strombus, but in the neritæ. There are some cochli which contain an animal like the small astacus, which is found in rivers; but they differ from them in having the inner part of the shell soft. Their form may be seen by examining dissections.