74 PHOLADIDiE. 



the mention of localities; individuals, however, have been 

 taken by Mr. Jeffreys, near Swansea, in floating wood, of 

 so immature a growth as to render their foreign origin at 

 least questionable ; and others are recorded by Mr. Thomp- 

 son as having been met with at Achill, in the west of Ire- 

 land. Dr. Turton states " that fragments of a wreck known 

 to have been buried in the ocean for nearly half a century 

 have lately (1822) been dragged up filled with magnificent 

 specimens in their most perfect state." 



2. T. NAVALis, Linnseus. 



Valves : — Body short, and rounded at its lower extremity ; 

 auricle in typical examples projecting laterally, never dorsally, 

 externally defined by the abrupt sinking of the level of its sur- 

 face, internally by a broad overlapping margin, which is more or 

 less appressed. 



Pallets small, testaceous, forked, and very solid at the base; 

 stalk cylindrical. 



Tube simple, strong, not chambered at its narrow end. 



Plate. I . figs. 7, 8, and Plate XVIII. figs. 3, 4. 



Beschreibung Hollandischen, See oder Pfahl-Wurms, (Numberg, 1733,) plate 3, 

 f. 19, 20. — RousSET, Observations sur les Vers de Mer, pp. 15, 16, 17, f. 1, 

 2, 3, 4, 10.— Ditto, English Translat., (1733,) pp. 13, 14, figs. 1, 2, 3, 4, 10. 

 — Belkmeer, Natuur-kundige Verhandel. Zee Worm, pi. 2, f. 7, "8, 9. — 

 Selluts, Hist. Nat. Teredin. pi. 2, f. 2, 3, 6. 

 Teredo naval is, Linn. Syst. Nat., ed. 12, p. 1267 (not of British authors). — 

 Home, Phil. Trans. 1806, pi. 12, f. 7,8, 9, 10.— Chiaje Me- 

 morie, vol. iv. pp. 23, 32, pi. 54, f. 2, 8 — Philippi, Moll. 

 Sicil. vol i. p. 2, and vol. ii. p. 3. 

 „ Batava, Spengler, Skrivt. Naturhist. Selskab. (1792), vol. ii. pt. 1, 

 p. 103, pi. 2, fig. C. 



The widely overlapping margin of the auricle, as viewed 

 internally, readily distinguishes the true, navalis of Lin- 

 nseus, from that erroneously regarded as it by the earlier 

 British conchologists ; a mistake which we are enabled to 

 rectify, not only by a careful comparison of the Teredines 

 with the figures of Sellius, on whose iconography the spe- 



