PSEUDOTOMA INTORTA. 213 



ReimtrJcs. — The generic name Pseudotoma was proposed by Bellardi in 1875 

 for a division of the Plenrotomidge Avithout a distinct keel or obtusely carinated, 

 having a large but shallow labial sinus, a nearly straight columella, and either 

 without, or with only a very short canal. 



P. intortii is one of the group of large Pleurotomidge characteristic of the 

 Miocene and Pliocene of Italy, as well as of the Oligocene and Miocene of other 

 parts of Europe. It is not known from the Coralline Crag or from Walton, and 

 the few specimens which have been met with at later horizons of the Red Crag, 

 principally from the Newbournian, are much w^orn, leading Wood to regard them 

 as derivative at that horizon. 



On the contrary, P. intorta is not only said to be abundant in the Miocene of 

 Belgium, but it has been found also in all the divisions of the Pliocene of that 

 region, especially in the Scaldisien of Antwerp, from which M. van de Wouver 

 has obtained more than 100 specimens, perfect and unworn. It would seem 

 probable, therefore, that it continued to exist in the western part of the Anglo- 

 Belgian sea as late at least as the Scaldisien period. 



The type of P. intorta originally described by Brocchi was a large, coarsely 

 sculptured shell, with a wide, misshapen mouth when adult, like those here repre- 

 sented from Waldringfield and Belgium (PI. XXVI, figs, 11, 12). A very similar 

 fossil was figured by De Koninck^ and afterwards by Nyst {op, cit., p. 510) under 

 the name of P. Morreni, resembling P. intorta in sculpture and form, but with a 

 different mouth. These were regarded by Bellardi, however, as varieties of the 

 same species, and with this I agree, especially as they are connected by the form 

 characteristic of the Lower Pliocene {argiles hleiies) of the Ligurian coast, a much 

 smaller shell with the general appearance and sculpture of Brocchi's P. intorta. 



I figure a specimen from my own collection of this variety which I obtained 

 some years ago in northern Italy. Fossils agreeing with the latter have been met 

 Avith occasionally in the Newbournian Crag, as at Waldringfield. _ 



Var. Morreni (S. V. Wood, non De Koninck). Plate XXVI, figs. 15, 16. 



1856. Pleurotoma intorta. Homes, Foss. Moll. Tert. Wien, vol. i, p. 331, pi. xxxvi, figs. 1, 2. 



1867. Pleurotovia Morreni, Speyer, Palaeontographica, vol. xvi, p. 196, pi. xxi. figs. 4, 5. 



1879. Pleurotoma Morreni, S. V. Wood, Mon. Crag Moll., 2u(i Suppl., p. 16, pi. ii, fig. 6. 



1907. Pleurotoma intorta, Eavn, Kongl. Danske Vid. Selslc. Skrift. [7], vol. iii, p. 343, pi. vii, fig. 4. 



1913. Pleurotoma intorta. Harder, Danm. Geol. XJnders0gelse [2], vol. xxii, p. 98, pi. ix, figs. 14, 15. 



Varietal Characters. — Shell much smaller and more delicate than the typical 

 P. intorta, the spire being more regularly and continuously conical ; whorls not so 



^ Mr. Bell informs me that he has found De Koninck's P. Morreni in the Suifulk Ijoxstones ; he 

 is inclined to think that other boxstone fossils may have been derived similarly from Oligocene 

 deposits. 



