In the preceding plate (plate 21) we have introduced to the attention of our readers a figure of that truly interesting rarity the reversed Voluta Pyrum, or Pear Volute, or as it is better known in the familiar language of the English collectors by the appellation of the High spired Turnip Shell. The figure there delineated exhibits a frontal view of this shell, in which the characteristic aperture of the mouth is displayed to advantage. And in order that nothing on our part may be wanting to complete our observations on this very valuable curiosity, we have been induced to insert in the present instance, a back or posterior view of the same shell. We have already entered so fully into the history of this shell in the description of the former plate, as to render it, we may presume, superfluous to dwell upon this subject further in the present instance. Our figure of the reversed shell, as in the former plate, is accompanied by a posterior view of a shell of the usual growth, (covered with its natural epidermis) and by the assistance of this figure, the contrary direction of the spiral wreath in the reversed shell becomes at once too obviously striking to escape attention. ------------------------------------------------------------------------ [Illustration: _23_ _London. Published as the Act directs, by E. Donovan & Mess.^{rs} Simpkin & Marshall Nov.^r 1, 1822._ ] ------------------------------------------------------------------------ ORNITHOLOGY. PLATE XXIII. TANAGRA TRICOLOR TRICOLOURED TANAGER var β. PASSERES. GENERIC CHARACTER. Bill conic, pointed, notched, nearly triangular at the base, a little inclining at the tip. SPECIFIC CHARACTER AND SYNONYMS. Shining green, beneath yellowish green; wing coverts violet: frontlet and upper part of the back black. _Var_ β. Crown and chin violet: neck, and sometimes rump, orange. TANAGRA TRICOLOR: viridis splendens, subtus viridi-flavescens, tectricibus alarum violaceis, capirostro dorsoque superiore nigris uropygio fulvo. _Lath. Ind. Orn. 428. 29._ TANAGRA TRICOLOR β. Tangara cayanensis varia cyanocephalos. _Briss. Sup. p. 62. t. 4. f. 2._ TANAGRA TRICOLOR: viridis, capite, mento, jugulo et pectore pallide thalassinis capistro nigro, cervice collique lateribus viridi-aureis, gulæ macula magna dorsoque nigris, pectoris fascia cærulea, abdomine crissoque ex flavicante viridibus. _Gmel. T. 1. p. 2. 891._ TANGARA varié à tête verte de Cayenne.—_Buff. Pl. Enl. n. 33. f. 1._ β TANGARA varié à tête bleue de Cayenne.—_Buff. Pl. Enl. n. 33. f. 2._ * * * * *