It is evident that these typical groups, whatever may be their nature, must present some very strong points of analogy to those in the circle of _Vertebrata_: and that such analogies should extend to the corresponding groups of the _Annulosa_. This we should expect, not only as the necessary result of a truly natural arrangement, but as a primary test, by which the correctness of any series of affinities must be tried. Now admitting that Quadrupeds and Birds shew the same typical perfection among the _Vertebrata_, as the Mandibulate and Suctorial Insects unquestionably do in the _Annulosa_, we have two beautiful analogies between these otherwise dissimilar groups, taken from one of the most important functions of nature. Quadrupeds and mandibulate insects are provided with jaws for tearing and masticating their prey, while in birds and suctorial insects, the mouth is lengthened into a proboscis, by which nourishment is imbibed by suction. These analogies are equally conspicuous among the _Molluscæ_. The _Phytiphages_ of Lamarck (of which the garden snail is a good example), are furnished with jaws and masticate their food: the _Zoophages_ of the same accurate observer, have their mouth elongated into a retractile trunk or proboscis, by which they pierce through other shells, and suck the juices of the inhabitant. To insist on the importance of these distinctions, employed as they have been to characterize primary divisions, is surely unnecessary. That they will be subject to considerable modification, in the subordinate groups, may naturally be expected: but we refrain at present from offering an opinion on the nature of such groups, dependant, as they must be, on greater anatomical knowledge than we yet possess. Nevertheless, until more direct analogies are discovered, than those here stated, we feel some confidence in employing them as _typical_ distinctions of the two great divisions of _Gastropod Mollusca_. * * * * * * [Illustration: PSARIS _Jardinii_ _Jardine's Saris._] PSARIS Jardinii. _Jardine's Saris._ ---- Family Todidæ.--_Nob_. Sub-family Psariana.--_Nob_. GENERIC CHARACTER. _Bill_ thick, strong, more or less depressed, culmen not elevated, both mandibles notched, the upper convex: _nostrils_ round, nearly naked: _rictus_ smooth; _mouth_ very wide. _Wings_ long, pointed, the second and third quill longest. _Tail_ short, even. ---- SPECIFIC CHARACTER. _Cinereous white; head, tail, and outer half of the wings, black: first and fifth quill equal: spurious quill none; orbits plumed._ In Mus. Nost. ----