R einereola. Head, cheeks, back, and scapulars, ashy-bluish ; wings and tail darker, but all the feathers of those parts are bordered with ash-colour. There is a small white spot on the wing, formed by the white towards the base of the quills, beginning with the fourth ; the first three have no white. All the lower parts are white, with the exception of the flanks, which are clouded with ash-colour. Bill coral-red, very strong, large, and as it were swollen (bombe). Feet ash-coloured. Length 4} inches. Inhabits Brazil, where it is said to be common.
- both Aplysia and Umbrella. De Blainville places it next but one to his Aplysians (his family Patc1loidat intervening) under the family Akers, the fourth of his third order Monoptenrobranehiata, of his second sub-class Paracephalophcvra Illonoica, of his second class Para cephalophora.
Forbes and Hanley make it the first family of the Gasteropoda opisthobranehiata. They observe that "this tribe may be considered intermediate between the two great sections of Gasteropoda. The shells of its mollusks are always convolute and more or less enveloped by the animal ; sometimes entirely invested, more rarely absent. Except in the case of Tornatella there is no operculum. The head of the animal is in the form of a single or lobed disk, and its lateral lobes are often greatly developed, so as in many species to serve as swimming organs. The foot is in some extremely small, in others a crawling disk of considerable dimensions. There are more than 150
species of this family known. They inhabit all parts of the world, and some of them are very widely diffused." The best account of the family that has yet appeared is by Mr. Arthur Adams in the Thesaurus Conelyliorum ' of Mr. G. B. Sowerby, Jun.
The following are illustrations of some of the Accra., Lamarck, Lobaria, De Blainville, has its body oval-oblong, sub-globular, appearing to be divided into four parts : one anterior for the bead and thorax, one on each side for the natatory appendages or fins, and one posterior for the viicera. The anterior fleshy disk terminates in an ap proach to a point near the middle of the body : the branehke covered by the mantle are so posterior that they seem to be almost at the extremity of the body, and below them would be the analogous situation for the shell, of which there is not even a rudimentary trace.
B,d&e. Lamarck assigned this name to those of the family which have the :dial entirely hidden iu the substance of the mantle. This shell is very open and delicate, and can hardly be said to have more than the first rudiment of the rolled-up form which is in Balla carried to greater perfection. Bullam aperta, Lam. (Bullma Planciana, Lam., in the early edition of the Syst, des Anim. sans Vert') ; Amygdala marina (Amande de Mer), Plane.; Balla aperta, Lin.; Balla aperta and