Historical Account ofTestaccological Writers. 173 



in number ; but under each of these are arranged numerous vari- 

 eties (as they are considered by this author), which, however, have 

 most of them been constituted distinct species in other Testaceo- 

 loo-ical works. These are illustrated by 400 figures, which have 

 in general the merit of correctness, but are not so elaborately 

 and strongly engraved as might be expected in a French per- 

 formance of that period, when, in this highly useful and elegant 

 art, France was not rivalled by any other nation in the world. 



There is a paper by this author in the Mem. de I' Acad, descrip- 

 tive of a species of Pholas which he observed in the timber of 

 ships in Senegal, and illustrated by very good figures of Teredo 

 navulis and the Pholades. 



In 1758 appeared the long expected third volume of the " De- 

 scriptio Thesauri Rerum Naturalium" of 



SEBA, 

 containing sixty-one plates of shells, some of which, however, 

 may be considered as useless, since they represent figures of birds, 

 &c. formed from those shells ; and most of them discover great 

 waste of engraving. There is still another subject of regret which 

 must occur to every person who peruses this sumptuous and 

 bulky work, namely, that most of the figures are common and 

 well known species, and calculated more for the amusement of 

 the eye, and for the surprise of the ignorant, than for the assist- 

 ance of a scientific naturalist. The descriptive part is not re- 

 markable for precision, nor is there any appearance of regular 

 system. One very useful purpose, however, may be said to have 

 been answered by the repeated representations of the same spe- 

 cies given by Seba, which is the possibility of seeing it in various 

 positions : the student being thus enabled to determine the agree- 

 ment of his specimen with those which are figured, more cer- 



tainlv 



