(12 • OLiviN.i;. 



Subthmily OLIVINE. 



Four illustrated monographies of the Olives have been pub- 

 lished. The earliest one is that of Duclos, forming part of 

 Chenu's " Illustrations Conchyliologiques;" next followed Reeve, 

 in the" Conehologica Iconica," vol. vi, issued in 1851. In 1870-71 

 F. P. Marrat contributed an elaborate monograph to Sowerby's 

 "Thesaurus Conchyliorum," beautifully illustrated by Mr. 

 Sowerby. Mr. Marrat, who does not believe in species, has, 

 unfortunately, in this group as in Nassa^ illustrated his views by 

 naming and describing a number of forms which certainly are 

 not species. Sowerby, in the reference to Plate 1, saj^s : " Mr. 

 Marrat 's intention is rather to produce evidence than to decide 

 upon the value of specific differences. In his study of affinities, 

 he has been led to register, and nominally to admit, as species 

 many forms which will perhaps appear to readers, as they do to 

 the editor, quite undistinguishable." The latest and best mono- 

 graph is that of Dr. H. C Welnkauff, completed in 1878, and 

 forming a portion of Kiister's " Conchylien Cabinet." Dr. Wein- 

 kauff also published a S3'stematic catalogue of the species, in the 

 " Jahrbiicher der Deutsch. Malak. Gesell.," in which he attempts 

 to arrange the species in accordance with their natural affinities 

 and to separate them into groups — which appear to possess some 

 value. I have mainly followed this catalogue in the present 

 monography ; adding, however, a number of specific names 

 overlooked by Weinkauff. 



H. and A. Adams and Dr. J. E. Gray have both proposed 

 elaborate series of genera and subgenera of the 01ivin?e ; most 

 of them, whilst serving to separate specified t^'pes, failing en- 

 tirely to furnish distinctive characters for other species which 

 are intermediate in form. Such names will be registered in my 

 synonj'mic index, scarcely requiring more particular mention 

 here. I have reversed the usual order of succession of the 

 groups by commencing with the smallest species of the Olives, 

 and proceeding through the Aneillarise to the Harp-shells : my 

 motive for this is to place next in succession to the Marginellae 

 those shells which, in size at least, most nearly approach them. 



The Olives are exclusively tropical animals. 



