12 OLIVA. 



mella fere omnino plicata, plicis calli antici 4 validis. — 

 Closely allied to 0, punctata, Mar. 



52. nobtlis (f. 120-122), Reeve. — 0. tremulina similis, 

 lateribus rectiusculis ; columella? plicis frequenter validio- 

 ribus ; spira magis pyramidata. — The variations in colour 

 and markings seem to be interchangeable between this and 

 0. tremulina. There is no constancy in the supposed charac- 

 teristics of form, such as the greater elevation of the spire 

 and straightness of the sides in 0. nob His, of which f. 120, 

 121 may be taken as typical. — Ed. 



53. pica (f. 111-113), Lamk. — Crassa, lata, ventricoso- 

 cylindracea, alba, pallidissinie tincta, maculis fuscis magnis 

 ad margines angulatis picta; columella tumida, plicis irre- 

 gularibus validis, callo postico elevato, callo antico tumido, 

 albo valide quadriplicate ; labio crasso, extus complanato. — 

 The creamy whiteness and tumidity of the columella and 

 outer lip, the pied character of the painting in the type, and 

 the solid fulness of the form, seem to give this shell a claim 

 to distinction. 



54. ponderosa (f. 104), Duclos. — 0. pica similis, latior, 

 brevior, crassior, pallide purpureo fluctuata; apertura intus 

 subaurea. — Is this more than a thickened and short variety 

 of O. pica ? — Ed. 



55. poephyritica (f. 105-110), Martini; O. erythrostoma, 

 Lamarck; miniata, B olten. — Quam 0. tremulina' magis acu- 

 minata, varie picta ; apertura intus aurantia. — Distinguished 

 from 0. tremulina and others of the group, by the orange 

 interior of the aperture. 



56. tremulina (f. 116-118), Lamk. — Oblongo-subcylin- 

 dracea, fulvo-rubescens, strigis undulatis et angulatis purpu- 

 reo-fuscis et fasciis duabus macularmn castanearum picta ; 

 spira conico-depressa, balteo diviso antice flammulato ; 

 columella, obsolete plicata, callo postico producto, callo antico 

 angusto,quadri- autquinqueplicato, frequenter aurantio tincto; 

 apertura intus pallide fulva, labio externo postice subangu- 

 lato, medio frequenter depresso et coarctato, aurantio picto. — 

 Although the typical variety is different enough from 0. 

 nobilis, it is almost impossible to distinguish the variously 

 painted and formed intermediate varieties. — Ed. 



57. Zeilanica (f. 129), Lamk. — Quam O. nobilis et 0. 

 tremulina magis angustata; labio tenui, intus fusco-margi- 



