550 PLIOCENE MOLLUSCA. 



Remarhs. — My attention was called to the essential difference between tlie 

 present shell and the recent and northern 8. grwiilanclica by M. de Bonry, who 

 expressed a strong opinion that Sowerby's specific name similis, by which it was 

 originally described and was at first known to Wood and to Nyst, should be revived. 

 The fossil distribution of these shells tends to support that view, showing that 

 8. similis is a characteristic though not a very abundant Red Crag species, 

 appearing first, so far as my experience goes, in the Coralline Crag of Boyton 

 and the Waltonian of Little Oakley and found not infrequently at later horizons 

 of the Red Crag. Generally it is unknown from the Pleistocene, either of Great 

 Britain or of Norway, though a few examples, broken or imperfect, have been 

 obtained from the Wexford gravels. It is a strong and solid shell and in marked 

 contrast with 8. (iroeiilandica, which is tliin and fragile. The latter and its variety 

 crebrlcostata are typical circnmpolar species with a wide northern i-ange, the first 

 being the most abundant 8cala of our Icenian and Pleistocene deposits, but unre- 

 corded from the earlier horizons of the Red Crag. Hence these shells seem to have 

 distinctly a zonal value. Moreover they differ in form and sculpture and are not 

 the same, though they belong to the same group. Whether the difference should 

 be regarded as specific or varietal may l)e left, perhaps, as a matter of opinion. 



Sub-genus TURRISCALA, de Boury, 1890. 



Scala (Turriscala) anglorum, Sacco. Plate XLVIII, figs. 33 ; Plate XLIX, 

 fig. 4. 



1871. Scalaria torulosa, Nyst, Ann. Soc. malac. Belg., vol. vi, p. 140, no. 321. 



1874. Scalaria torulosa, Van den Broeck, Ann. Soc. malac. Belg., vol. ix, p. 119. 



1879. Scalaria torulosa, S. V. Wood, Mon. Crag Moll., 2nd Suppl., p. 25, pi. ii, fig. 13. 



1890. Scalaria torulosa, C. Reid, Plioc. Dep. Brit., p. 25fi. 



1891. Turriscala torulosa, var. anglorum, Sacco, Moll. Terr. Terz. Pieni., pt. ix, pp. 77, 79. 

 1911. Scalaria (Acirsa) torulosa, A. Bell, Jouru. Ipswich Field Chib, vol. iii, p. 16. 

 1918. Scala (Turriscala) anglorum, de Boury, MS. 



Specific Characters. — Shell turreted, thick, imperforate ; whorls but slightly 

 convex ; spire elongate, subconical ; ornamented Ijy well-marked longitudinal 

 costse not so wide as the interspaces, and l)y very fine spiral lines ; suture slight ; 

 base angulated; mouth subcircular ; peristome continuous with a strongly 

 thickened margin. 



Dimensions. — L. 25 — 28 mm. B. 8 — 9 mm. 



Distrihution. — Not recorded living. 



Fossil: Coralline Crag: Boyton. Newbournian : Waldringfield. 



Remarks. — A single specimen of Scala from the Coralline Crag of Boyton, 

 obtained by Mr. Charlesworth some years ago, was described l)y Wood under 



