﻿PROSOBRANCHIATA. 



311 



No. 237. Pleurotoma turbida. Solander. Tab. XXXII, fig. 2, a — c. 



Murex tdrbidus. Sol. 1766. Brand., Foss. Hanton, p. 19, fig. 31. 

 Pleurotoma colon. Sow. 1816. Min. Con., vol. ii, p. 106, t. 146, f. 7, 8. 



— cataphracta. Morr. 1843. Cat. Brit. Foss. ( 1st Edit.), p. 157 ; (non Broce.) 



— colon. Morr. 1843. Cat. Brit. Foss. (1st Edit.), p. 157. 



— turbida. Morr. 1843. Cat. Brit. Foss. (1st Edit.), p. 157. 



— colon. Bronn, 1818. Index Paheont., p. 1003. 



— turbida . Bronn, 1848. Index Palseont., p. 1011. 



colon. D'Orb. 1852. Prod, de Paleont., 25 c Etage, p. 359, No. 409. 



— tdrbidus. jyOrb. 1852. Prod, de Paleont., 25 e Etage, p. 359, No. 413. 



— colon. Morr. 1854. Cat. Brit. Foss., p. 269. 



— turbida. Morr. 1854. Cat. Brit. Foss., p. 270. 

 Nec. Pleurotoma turbida. Lam. Encycl. Method., t. 451, f. 8. 



Nec. — — Lam. Anim. sans Vert., vol. vii, p. 97, No. 5. 



Nec. — colon. Desk. 1 824-37. Coq. foss., &c, de Paris, vol. ii, p. 4 92, t. 66, f. 4, 7. 



Nec. — Nyst, 1835. Rech. coq. foss. d'Anvers, p. 28, No. 26. 



Nec. — — Nyst, 1836. Rech. coq. foss. de Hoesselt, &c, p. 30, No. 78. 



Nec. — — De Kon. 1837. Coq. foss. de Basele, &c. p. 20, No. 19. 



Nec. — turbida. Nyst, 1843. Coq., &c, foss. de Belg., p. 513, t. 40, f. 8. 



Nec. — Grat. 1847. Conch, foss., &c, de l'Adour, Atlas, t. 3, No. 21, f. 26. 



P. testa oblongd, sub-fitsiformi, turritd, undique concentrice lineatd ; spird elevatd, 

 obtusd : anfractibus depresso-convexis ad humeros in juventd carinam obtusam crenatam 

 transversim sulcatam, gerentibus, cleinde curvo-plicatis ; marginibus posticis concavis, ad 

 mturam scabro-plicatis et duabus vet tribus lineis elevatis, acutis, cinctis ; ultimo anfractu 

 sub-conico ; lineis concentricis supr a margines et humeros anfractu urn confertis, exilissimis, 

 sub-aqualibus ; supra medias partes nonnidlis crassis, prominentibus, fastigiiformibus, dis- 

 tantibus, cceterum exilibus ; omnino sub-clathratis -. aperturd elongato-ovali, in canali bre- 

 vissimo, ad basin prof unde emarginato, exeunte ; labro tenui, sub-semicirculari ; columella 

 contorfd, callosd, cristatd ; sinu latiusculo, prof undo, marginibus sub-parallelis, ad humeri/ m 

 collocato. 



Var. |3 testa anfractibus ad humeros fortiter tuberculatis ; lineis concentricis mediants 

 et anficis sub-denticulalis. 



Shell oblong, sub-fusiform, turreted, concentrically ridged and lined ; spire rather 

 thick, pointed, and much elevated, forming nearly 3-5th parts of the entire length. 

 The whorls, nine or ten without the pullus, are depressedly convex ; in the young state 

 they present round the shoulders an obscure, obtuse keel, bearing a closely set series 

 of narrow, vertical, slightly curved tubercles, defined at each end, and occasionally 

 also traversed by fine, raised, thread-like lines ; these tubercles and the keel gradually 

 become less prominent as the shell enlarges, and frequently altogether disappear 

 on the last two or three whorls, which then present only a series of numerous verv 

 fine, thread-like, curved plications, formed by the successive, rounded extremities of 



