1919. J E. W. Vredenburg : Shells of the family Doliidœ. 165 



Rumphiiis a l'île d'Amboine ; Martini l'indique aux îles de Tranquebar ; et Petiver 

 a l'île de Luçon, l'une des Philippines." 



We may now add a few comments on this admirable description. 



(i) From the very first sentence, Bruguière, in accordance with the best models 

 of modern descriptions, adopts the practice, too often neglected even by modern 

 writers, of giving detailed measurements of the species. Judging from the figures 

 quoted, the average diameter of large specimens should be three inches, or about 

 75 mm., which agrees with what is generally observed in the species above described 

 as Dolium tessellatum, while the exceptionally fine specimen specially selected by 

 Bruguière for description measured four and a half inches, or about 115 mm. in 

 diameter, a size probably never attained, so far as is known, by Dolium maculatum, 

 and only inferior by about 20 mm. to that of the magnificent specimen figured in 

 Reeve's monograph as Dolium fimbriatum. Themost essential point with reference 

 to the present enquiry is that the detailed measurements given by Bruguière are 

 those of the particular specimen about to be described. Clearly then, this description 

 is not a generalised diagnosis built up from a number of specimens or uniting the 

 separately published features of previous descriptions. It is a detailed description 

 of a single specimen, and obviously therefore cannot refer to more than one species. 

 Whatever may be that species, it is clear that the merest glance through the very 

 first sentence suffices to dispose of the totally undeserved criticism of Reeve, of 

 Küster, and of Tryon, regarding the alleged composite character of Dolium tessellatum. 



(2) The dimensions recorded in the first sentence already exclude almost all 

 possibility of referring Bruguière' s type to Dolium maculatum. The number of ribs 

 as recorded in the second sentence irrevocably confirms its attribution to the shell 

 described in the present work as Dolium tessellatum ; for even taking into account 

 any possibility, however improbable, of mistaking, on the body-whorl, some of the 

 ribs of the second order for primary ribs, the number recorded on the spire-whorls, 

 namely four, settles once for all the specific attribution of the shell under considera- 

 tion. Dolium tessellatum, as understood in the present work, does not always exhibit 

 as many as four ribs on the spire-whorls, but Dolium maculatum never shows more 

 than three ; and it is beyond all possibility of a doubt that the type described by 

 Bruguière is Dolium tessellatum as here interpreted. The shape of the ribs, the 

 shape and size of the intervals, the occasional presence of a median line, and the 

 number of ribs on the body-whorl, as described by Bruguière, are all in total agree- 

 ment with this interpretation. 



(3) This sentence refers to the absence of a deep suturai channel such as charac- 

 terises Dolium galea or D. olearium. Sentence (4) needs no comment. 



(5) Not only has Bruguière given a perfectly precise description of the charac- 

 ters of the labrum, but he has recorded with admirable lucidity the history of its 

 development throughout the successive stages of growth of the shell. It is unneces- 

 sary to comment on the wonderful insight of the great naturalist at a period when 

 the science of zoology was still in its formative period. It is nevertheless astonish- 

 ing that so remarkable an observation should have passed unnoticed by all his 



