64 PHOLADIDiE. 



The essay of Sellius is highly original : it is a very per- 

 fect monograph for its time. He was the first to attempt 

 to develope the organisation, internal and external, of the 

 Teredo, and he illustrated his book with elaborate figures 

 from his own drawings, which, as well as his descrip- 

 tions, are executed in good faith and with judgment. 

 It must be borne in mind that the nature of the Teredo 

 was entirely misunderstood, and its history lost in obscu- 

 rity and fable, at the time when Sellius attempted to work 

 out the subject in all its details. No after-writer had 

 equal difficulties to contend with, for he cleared the way. 

 Few monogTaphs on single species are even now attempted 

 to be worked in such elaboration; and the example set by 

 this civil historian, turning his attention suddenly to a dif- 

 ficult zoological research, is too remarkable an event in mala- 

 cology to be passed over without full praise. He was the 

 first to hold and prove that the Teredo is a mollusk, thus anti- 

 cipating Adanson, and shewing more sagacity than Linnaus, 

 who long after persisted in placing the ship-worm alongside 

 of the DentaUum and the Herpula. Adanson was not aware 

 of the determination of Sellius; and in his "Natural History 

 of Senegal," (1757,) claims to have arranged the Teredo 

 among bivalve Testacea. With his usual ability he at once 

 recognised both the true nature of the several external parts 

 of the animal, and the true position of the genus alongside of 

 Pholas. The truth of Adanson's view was more completely 

 demonstrated by Cuvier, and tardily admitted by Lamarck. 

 Except in England, where the followers of Linnaus forgot 

 the spirit and adhered to the letter of the works of the il- 

 lustrious Swede — a proceeding most contrary to the examjile 

 he had set in his own course — the molluscan nature of Te- 

 redo, and its place alongside of Pholas, was everywhere un- 

 derstood, in the early part of the present century. The 



