that derive their nourishment from decomposed vegetable or animal matter. For the most part, only two of the membranes which enter into the general composition of the tunic of the intestinal canal can be detected here, the innermost of which is almost corneous and much folded. These folds are not accidental, but are arranged in a certain order, according to the genera and families. The gizzard is wanting in the larvæ of all insects which go through a complete metamorphosis. The chylific ventricle, (Plate II. fig. 2 and 3, d.) is the ensuing dilatation of the intestinal canal; an important cavity which, upon the whole, may be regarded as most nearly corresponding to the stomach of the vertebrata. The above name, assigned to it by M. Léon Dufour, is exactly expressive of its function, which is to contain the food, now reduced to a homogeneous and impalpable pulp, till it undergo the process of chylification. Its capacity is considerable, either arising from its width or length. Its termination behind is indicated by the insertion of the biliary vessels, or by a constriction separating it from the small intestine. In form, it is always more or less tubular, or tending to oval, but even within these limits the shape varies much. In the common cockchafer, (Pl. II. fig. 3 d,) it is contracted behind into a long tube, and twisted into several circumvolutions—a mode of disposition which it frequently exhibits in a still more complicated manner in some of the other orders. One of the most distinctive and remarkable characters of this ventricle, is the palpillæ or small
