ORTHONYCHIA. 49 



1858. Captjlus acutus, Giebel, Sil. Faun. TJnterharz., p. 18, pi. iii, figs. 14, 



17, 18. 

 1858. — BiscHOFii, Gielel. Ibid., p, 19, pi. iii, figs. 1, 3, 13. 



1858. — ACUTTSsiMirs, Giebel. Ibid., p. 19, pi. iii, fig. 9. 



? 1858. — SELCANus, (rieJe^. Ibid., p. 20, pi. iii, fig. 8. 



1861. Plattceeas conicum. Hall. Desc. New Species Fos., p. 3. 

 1861. — QUiNCYENSis, McChesney. Desc. New Palseoz. Foss., p. 90. 



1865. — _ _ Ibid., Illust., pi. vi, figs. Qa, h. 



1867. — QUiNCTENSE, McChesney. Trans. Chicago Acad. Sci., vol. i, 



p. 49, pi. vi, fig. 6. 



1868. — (Oethontchia) QuiNCTENSE, Jfec^-awri? TFor^/ien. Geol. Surv. 



Illinois, vol. iii, p. 510, pi. xv, 

 figs. 5 a, b. 



? 1868. — — SUBPLICATUM, Meek and Worthen. Ibid., 



p. 457, pi. xiv, figs. 4 a' — c. 



? 1868. Capulus conicus, Trenkner. Paleont. Novitat., pt. 2, p. 21, pi. vii, fig. 14. 



1878. — HEKCXNicus, Kayser. Abhandl. G-eol. Specialk. Preuss, Baud 2, 



pt. 4, p. 89, pi. xiv, figs. 1 — 14 ; and 

 pi. XV, figs. 10—11 b. 



1879. Plattceeas (OETnoNXCHiA) conicum, Hall. Pal. N. Y., vol. v, pt. 2, 



p. 3, pi. i, figs. 13—23. 

 ? 1885. — SELCANUS ?, Maurer. Abhandl. Grossh. Hessisch. Greol. Landes., 



vol. i, pt. 2, p. 242, pi. X, figs. 23, 24. 

 1889. Platyceeas acutum, Barrois. Mem. Soc. Geol. Nord., vol. iii, p. 198, 



pi. xiii, fig. 7. 

 1889. — ACUTissiMUM, Barrois. Ibid., p. 199, pi. xiii, fig. 8. 



1889. — heecywicttm, Barrois. Ibid., p. 189. 



? 1889. — SELCANTJM, Barrois. Ibid., p. 190, pi. xii, fig. 7. 



? 1889. — DUBIUM, Barrois. Ibid., p. 191, pi. xiii, fig. 1. 



1893. — CULTELLUS, TscJiemyschew. Mem. Com. Geol., vol. iv, No. 3, 



p. 157, pi. i, fig. 27. 



Description. — Shell elongate, not involute, very variable. Apex blunt, vertical, 

 situate somewhat in front of the perpendicular from the centre of the plane of the 

 mouth. Whorl more or less conical or fusiform, increasing with variable rapidity, 

 and generally bearing several concavities and convexities, which radiate from the 

 apex, and which render the oral margins irregularly lobate. Mouth large, sub- 

 oval. Surface apparently marked by indistinct growth-lines. 



Size. — Height 12 mm., width 12 mm. 



Localities. — There is a specimen from Sowden, near Barnstaple, and one from 

 Top Orchai'd, in the Barnstaple Athenseum ; another from Top Orchard in the 

 Woodwardian Museum ; and three, respectively from Pilton, Fremington, and 

 Marwood Parish, in the Porter Collection. 



BemarJcs. — The above specimens vary very greatly in shape. No two of them 



G 



