Under the genus _Solen_ (vulgarly called Razors or Pods) are comprehended a variety of shells having the common character of both extremities open or gaping when the valves are together, yet differing materially in their form, teeth, and general appearance: some are long, slender and straight; others more or less curved; a few short and oval, or with one end only lengthened. Modern writers have, however, retained nearly all these in the genus as left by Linnaeus; and this method for the present is more desirable than that of creating a multiplicity of genera. Dr. Turton, in his very useful Conchological Dictionary, enumerates thirteen species as found on the British coast, including the _Solen Novacula_ of Montagu, which the Doctor suspects is not truly a species. The original specimens which Montagu described I have carefully inspected at the British Museum, and have no doubt in my own mind they are in reality no other than _S. Siliqua_ with one of the cardinal teeth broken off; a circumstance which, from their fragility, frequently happens, even in opening the recent shell. _Solen ambiguus_ was first described by Lamarck, who says it is from North America. Two or three specimens are in my possession; but it is a rare species, much thicker, and with larger teeth than any other; the epidermis is pale-brown, and in some parts obliquely lineated. * * * * * Pl. 56 [Illustration] RAMPHASTOS vitellinus. _Sulphur-and-white-breasted Toucan._ * * * * * GENERIC CHARACTER.--See Pl. 45. * * * * * SPECIFIC CHARACTER. _R. niger, gula flavo-aurantia; lateribus auribusque albis; fascia pectorali tegminibusque rubris; rostro nigro fascia basali caerulea, culmine subcurvato convexo, lateribus incrassatis._ Black; throat yellowish-orange; the sides and ears white; pectoral bar and tail-covers red; bill black, with a blue basal belt, the top convex and but slightly curved, the sides thickened. R. vitellinus. _Illiger_ ---- Le Pignancoin. _Vaill. pl._ 7. _Var._? Le Grand Toucan a ventre rouge. _Vaill. pl._ 6. * * * * * The descriptions of Dr. Latham, and the compilations of Dr. Shaw on the various species of Toucans, are so confused, and their synonyms so inaccurate, that it is quite impossible to quote them in reference to this bird; but which I am informed has already been distinguished by the celebrated Illiger as a distinct species, under the name here adopted.