472 Mr. F. P. Marrat on proposed new Species o/*01iva. 



usque in marginem peristoraatis producta ; perist. pallido, mar- 

 gine subinerassato, undique expanso. 

 Long. 6 1 lin., diam. (anfract. penult.) I5 lin. 



Hab. Mososeki. 



A very pretty slender species, with several transverse im- 

 pressed lines on the whorls. 



L V. — Observations on some proposed new Species of Oli va. 

 By F. P. Marrat. 

 In the May Number of the 'Annals/ p. 344, Mr. Ponton, of 

 Clifton, has taken exception to the whole of my proposed new 

 species of the genus Oliva. It is, I think, a grave offence to 

 occupy the pages of the '■ Annals ' with conclusions hastily 

 adopted ; and I therefore beg permission to clear myself of the 

 implied charge of having done so. 



The collection from which the materials of my paper were 

 taken has been the work of several years : it contains of each 

 of the more variable species from forty to one hundred or more 

 specimens, and includes, with the exception of a very few (per- 

 haps five or six), every species and every named variety that 

 I have been able to find figured or described in the works of 

 Lamarck, Sowerby, Chenu, Gray, and Reeve. In such a 

 series, numbering some thousands of specimens, it might 

 reasonably be expected that undescribed forms would occiu* as 

 much deserving to be named as many of the forms identified 

 by the above-named authorities. My supposed new forms 

 have been selected with much care and reserve ; and all pre- 

 tensions to be able to make positive assertions on the extent or 

 limit of particular species I freely resign to others. 



Mr. Ponton states that colom- altogether fails as a specific 

 character in this genus. It is not surprising that an inspection 

 of such species as 0. ispidxda^ Linn., 0. irisans^ Lam., 0. 

 maura^ Lam., and 0. ventricosa^ Soland., should produce an 

 impression of this kind ; but nowhere amongst the Gastero- 

 poda are the indications afforded by colour of more value than 

 in the genus Oliva. Even slight differences of shade may 

 often afford a clue leading to the recognition of affinities after- 

 wards abundantly substantiated by more permanent characters. 



I find in Reeve's monograph, after the description of O. 

 volvarioidesj the following remark : — " The uniform chestnut 

 colouring appears to be peculiar to the species in this instance." 

 At the same time Mr. Reeve forgets to tell us that Duclos has 

 figured a nearly white variety on the same plate ; and also that 

 there is a variety of 0. lepida^ Duclos, of a uniform chestnut- 



