132 PLIOCENE MOLLUSCA. 



1848. Trophon muricatus, S. V. Wood, Mou. Crag Moll., pt. i, p. 50, tab. vi, fig. 5. 



J.853. Troptwn muricatus, Forbes and Hauley, Brit. Moll., vol. iii, p. 439, pi. c.\i, figs. 3, 4. 



1867. Tro])hon muricaius, Jeffreys, Brit. Couch., vol. iv, p. 316, jil. Ixxxiv, fig. 4. 



1873-75. Tro])hon muricatus, Segueuza, Boll. E. Com. Geol., vol. iv, p. 348, 1873 ; vol. vi, p. 340, 1875. 



1874. Troplwn muricatmn. Van den Broeck, Ann. Soc. Mai. Belg., vol. ix, p. 292. 



1882. Troplion mtmcatus, Bucquoy, Dautzenberg et Dollfus, Moll. Mar. Rouss., vol. i, p. 39, pi. vi, 



fig. 7. 

 1887. Tro])Jion muricatus, Kobelt, Icon, sclialentrag. europ. Meerescoucb., p. 30, pi. vi, figs. 18, 19. 

 1890. Trophon muricatus. Cams, Prodr. Faun. Medit., vol. ii, p. 384. 

 1912. Trophon {Trophonopsis) muricatus, Dautzenberg et Fischer, Camp. Scient. Pr. Monaco, vol. 



xxxvii (MoUusques), p. 154. 



Specific Characters. — See Mon. Crag Moll., pt. i, p. 50. 



Dimensions. — L. 15 mm. B. 6 mm. 



Distribution. — Recent : western coasts of Great Britain and Ireland ; Atlantic 

 coasts of France, Spain, and Portugal; North America (Gould). 



Fossil : Coralline Crag. Waltonian : Walton-on-Naze, Beau- 

 mont, Little Oaklej (very abundant). Newbournian: passim. Butleyan: BaAvdsey, 

 Butley, Holleslej, Alderton. Wexford gravels. Middle Glacial sands : Billockby. 

 Portrush, Dublin, Isle of Arran. Scaldisien : Belgium. Upper Pliocene and 

 Pleistocene : Sicily. 



Eemarlis. — This well-known British auvd Mediterranean species occurs in the 

 Gedgravian and Waltonian stages of the English Crag, being exceedingly common 

 at Little Oakley, but less abundant in the Newbournian and Butleyan. 



It is one of those southern shells which, common in the older beds of the Crag, 

 gradually became rare and eventually disappeared from the Pliocene basin. It has 

 not been recorded from the Norwich Crag or from any of the later East Anglian 

 deposits except the Middle Glacial sands, nor is it known as living in the North 

 Sea. 



Out of several hundred specimens I have obtained at Oakley the large majority 

 are of the type form, but I have found also at that place a number of others which 

 present more or less distinct variation from it and deserve notice. 



The Belgian fossil figured by Nyst in 1881 as T. muricatus (see p. 133) does 

 not seem to be the characteristic form of tlie Scaldisien Crag. The specimens of 

 this species in my own collection from Antwerp, and, as far as I could see, in that 

 of Mr. van de Wouver, are of the usual type. 



Var. valida (Monterosato), nov. Plate XII, fig. 21. 



— Trophon muricatus, var, valida, Monterosato, MS. 



Dimensions. — L. 12 mm. B. 5 mm. 

 Distribution. — Not known living. 



Fossil : Waltonian Crag : Little Oakley. Pleistocene : Sicily. 



