23G SOLARIUM. 



postremum laevigata. Basis pars exterior satis lata, cingulis an- 

 gustis pluribus (3-4) ornata (fortasse in exemplis senioribus ob- 

 soletis). Crense umbilici satis ampli parvre, permultse, tantum a 

 costis alia? partis basis rudibus radiantibus sulco unico volvente 

 divisrc. Obs. In the only recent example (brilliant in colour, semi- 

 translucent in texture) of this beautiful fossil at present known, 

 the keel protrudes downwards, the ribbed portion of the base is 

 convex, and the belted area is somewhat concave. The absence 

 of an umbilical belt is a striking peculiarity. 



** Sect. B. Philippia. 



22. hybeiduai (f. 39, 40, 41, 42, 43), Linn. — T. subtlepresso- 

 conica, la;vis : sutura angusta. Anfractus pauci, fulvi rufi vel 

 fusci, superne tumidi et nonmuiquam maculis albis obsoletis 

 variegati ; inferne nonnunquam aliquantum gradati et cingulis 

 geminis albo articulatis angustis semper instructi. Cingulum 

 peripherale articulatum, jacens inter vicina 2 cingula minora 

 (quorum inferius depressum raro est articulatum), rotundatum. 

 Basis valde convexa, nonnunquam juxta cingulum angustum 

 articulatum, quod cingulum umbilicale candidum latissimum am- 

 plectitur, vitta alba, pallidave ornata. Ciena; umbilici modice 

 tantum coarctati parvse, pennulta;. — Var.. undata, f. 42, 43. 

 Alba, strigis angustis undatis fuscis, vel fusco-luteis, undique ra- 

 diata, eodemque colore infra suturam ornata ; basis zonis 1-2 

 similibus, sed pallidioribus, nonnunquam picta ; maculis albis zo- 

 nata. Anfractus superne albo late et confertim maculati; cin- 

 gula alba, remota, etiam strigis communibus ornata. — Var. 

 australis. Conoidea, vel depresso-conoidea. Anfractus fulvo- 

 fusci seu rufo-brunnei, aut lineis saturatioribus, aut inferne ma- 

 culis albis (ssepe angulatis satisque magnis) et superne maculis 

 parvis confertis, circumcincti. Peripheriae sulcus latior quam 

 cingula ejus angustissima. Color basis (etiamque anfractuum 

 apicalium) in lineis saturatioribus et pallidioribus spiraliter ordi- 

 natus. Obs. The epidermis is occasionally disposed in spiral lines 

 near the mouth. The type of Layardi is only a young, and hence 

 depressed form of this variable species. — Var. undata, f. 42, 43, 

 and var. australis, present variations in colour and marking. 



23. oxyteopis (f. 46, 47), Adams. — "T. conico-depressa, dis- 

 coidea, late umbilicata, albida, luteo fuscoque variegatim picta, 

 nucleo magno albido vitreo, anfractibus planiusculis, transversim 

 lineatis, ad suturas cingulis 2 elevatis instructis ; ad peripheriam 

 acute angulata, cingulis 2 cincta, basi convexiuscula; margine 



