A small reversed species, unbanded, and scarcely exceeding half an inch in length. In form it perfectly resembles the green variety of _Bulimus citrinus_. The three specimens in our museum vary in colour from a light olive brown, to a livid purple which lies in longitudinal shades, and gradually changes, on the spiral whorls, to white; suture marked by a line of deep orange brown; aperture white, tinged with purple. * * * * * * [Illustration: MURICINÆ. Pl. 3. MUREX (PHYLLONOTUS) _Imperialis._ _var. a._] MUREX (_Phyllonotus_) Imperialis, _Imperial Murex. var. a._ ---- Genus Murex. Sub-genus Phyllonotus. _Nob._ SUB-GENERIC CHARACTERS. See pl. 100. ---- SPECIFIC CHARACTER. See pl. 67. ---- In a popular work like this, we wish to consult the taste of the amateur, no less than of the philosophic naturalist; and with this object we have delineated a beautiful variety, having the aperture rose colour, of the _Murex imperialis_ already figured at pl. 67 of our second volume. It was then in the possession of Messrs. Stuchbury, and was nearly the only one, among very many of the usual orange-mouthed specimens, which came to their hands. We have already intimated that the series of types in this genus, (see pl. 100) besides possessing innumerable analogies in the class _Mollusca_, exhibits a most singular one with the series of vertebrated animals; four of which can be traced by comparing them with four of the classes of the vertebrated circle. Commencing with _Phyllonotus_, we may call them, from the hideous and repulsive aspect of many of the species, the _Reptile_ type, as the name given to one (_Murex scorpio_), sufficiently intimates. In the tooth-like spines of _Murex tenuispinosus_ we see some resemblance to the teeth of quadrupeds: the _Murex haustellum_ has been well compared to the head of a snipe, while in the fin shaped varices of _Murex pinnatus_, we have a representation of the _fish_. If the analogy between _Centronotus_ and the _Amphibia_ cannot be traced, it is because the latter has so few forms; but the Hedgehogs, which represent the _Amphibia_ in the circle of Quadrupeds, are again represented under the form of a shell, in the sub-genus _Centronotus_. These analogies, however remote are unquestionably natural, _because they follow each other in a uniform series_. Thus, Murex represents Mammalia. Haustellaria Aves. Pterynotus Pisces. Centronotus Amphibia--Hystrix. Phyllonotus Reptilia. * * * * * * [Illustration: MARIUS (PETREUS) _Thetys_. _Larva & Pupa_.] MARIUS (_Petreus_) Thetys, _Thetys Butterfly_. ---- Family Nymphalidæ. Sub-family Paphianæ. Genus Marius. Sub-genus Petreus. (Heliconian Type.) SUB-GENERIC CHARACTER. Superior wings long, horizontally lengthened; Larva naked, with 3, 4 fleshy filaments on the body. ---- SPECIFIC CHARACTER.