246 SPURIOUS SCAPHOPODA : SERPULID.E. 



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

 from Blainville. Subsequent developments ensued, further compli- 

 cating the question. Gray (P. Z. S., 1847, p. 159) evidently thought 

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

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

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

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

 Defrance. 



In short, Entaliwn 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. mosa; 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. Lethpea 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. dujiUcatum 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. 

 PI. 37, fig. 18. 



Described from one specimen occurring " in a friable, brown 

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



