An oblong rectangular, a circular and an oval type, the latter being either FIG.
It is oval in shape, and retains its medieval fortifications.
' Shell globular and ventricose; aperture oval and canaliculated; operculum spiral.
The innermost, the coprodaeum, is an oval dilatation of the end of the rectum, and attains its greatest size in those birds whose faeces are very fluid; it serves entirely as the temporary receptacle of the faeces and the urine.
The fish is also said to be represented in the oval-shaped figure, pointed at both ends, and formed by the intersection of two circles.