246 SPURIOUS SCAPHOPODA: SERPULID^E. 



obviously due to a desire for pure Latlnity, his information being 

 from Blainville. Subsequent developments ensued, further compli- 

 cating the question. Gray (P. Z. S., 1 847, p. 159) evidently thought 

 that the apical tube was due to repair of injuries, and he establishes 

 a genus Entails with Dentalium entails as type. This of course is 

 totally different from Sowerby's " Entalis" which was a Latiniza- 

 tion of " Entale," and based ultimately upon the type of Entallum 

 Defrance. 



In short, Entallum Defrance, Entale Blainville and Entalis Sow- 

 erby pertain to Pyrgopolon, a worm ; Entalis Gray and later authors 

 is a form of Dentalium. See also page 37 of this volume. 



The irregular growth and two-layered structure of these shells is 

 conclusive evidence that they belong to the Serpulid worms. A num- 

 ber of species have been described under various generic names 

 P. mosce Montf., Dentalium clava Lam., D. crassum Desh., Phare- 

 trium fragile Konig but they are probably variations of one or two 

 Protean species. D. tricostatum Goldf. is apparently a Pyrgopolon. 



Dentalium browni HISINGER, 1837. Lethsea Suecica seu Petrifak. 

 Sueicise, p. 21, pi. iv, fig. 9 (not seen by us). 



Dentalium clava LAMARCK, 1818. Anim. s. Vert., v, p. 346. 



Dentalium crassum DESHAYES, 1825- Mem. Soc. Hist. Nat. 

 Paris, ii, p. 373, pi. 18, fig. 20. 



D. duplicatum BLAINVILLE, Man. de Mai., p. 628 (1825) ; a 

 nude name. 



Pyrgopolon mosce MONTFORT, 1810* Conch. Syst., i, p. 394-396. 



Dentalium tricostatum GOLDFUSS, 1844. Petrifac. German., iii, 

 p. 3, pi. 166, fig. 11. Cretaceous, Westphalia. 



Dentalium wilsoni FRASS, 1867. Jahresh. Nat. Kund. Wiirttem- 

 berg, Jahrg. xxiii, p. 239, pi. iv, fig. 12. 



Cretaceous, Marsaba, Palestine. 



SPIRODENTALIUM Walcott, 1890. 



Spirodentalium WALOOTT, Proc. U. S. Nat. Mus., xiii, p. 271. 



" Shell tubular, curved, opened at both (?) ends, attenuated pos- 

 teriorly ; aperture circular, surface spirally striated." 



Type S. osceola Walcott, (I. c., pi. 20, f. 12) from the upper por- 

 tion of Cambrian (Potsdam terrane), Osceola Mills, Wisconsin. 

 PL 37, fig. 18. 



Described from one specimen occurring " in a friable, brown 

 sandstone as cast and the matrix." " Longitudinally marked by 



