TL'KBONILLA (PYRGOSTELIS) FORMOSA. 56D 



Specific Characters. — Shell small, slender, subulate; Avhorls 8 — 10, flattened, 

 ornamented by numerous inconspicuous cost* and thread-like spiral lines ; spire 

 elongate, regularly taj)ering ; suture well-niarked, oblique, slightly channelled but 

 not deep ; mouth small, short, subcircular, angulate above ; outer lip thickened, 

 smooth within. 



Dimensions. — L. 7 — 8 nun. B. 1'5 nun. 



Distribution. — Not known living. 



Fossil: Coralline Crag: Sutton. Casterlien, Scaldisien : 



Beloium. Scaldisien : Holland. 



Bemarlis. — In the Museum at York there are two very similar specimens, one 

 of them marked T.filosa and the other T. siniilis. They were both found in the 

 Coralline Crag at Sutton, the first having come to that institution through the late 

 Edwd. Charles worth, the second through Alfred Bell. They are very nearly 

 alike — indeed, Jeffreys regarded T. similisas a variety of T.p'lusa. Wood, however, 

 with the two authorities named, who were at the time in close correspondence with 

 him, regarded them as specifically distinct. Our specimen is somewhat worn, but 

 under a microscope the spiral markings are clearly shown to be simple and 

 equidistant, and to extend over the base of the shell. In 7'. sirnilis, on the 

 contrary, they are usually double, as stated below. Wood states he had o1)tained 

 about twelve specimens from the Coralline Crag of Sutton, doubtless from the bed 

 of small shells often here alluded to, and that the longitudinal costa3 are often 

 nearly obsolete. The mouth is shorter and more nearly circular in T. fiJosa than 

 in T. siniilis. 



Prof. Ed. Forbes identified this form with Parfhenina vayicosa,a,n JEgean shell 

 described by him in 1843,* l)ut Wood doul)ted the correctness of this view, as 

 apparently did Jeffreys, who in 1871 adopted Wood's name witliout comment. 



Turbonilla (Pyrgostelisj formosa (Jeffreys). Plate XLIX, fig. 30. 



1848—67. Odostomla formosa, Jeffreys, Auu. Mao-. Nat. Hist. [2], vol. ii, p. 347, 1848 ; Brit. Conc-h., 



vol. iv, p. 164, 1867. 

 1853. Chemnitzia formosa , Forbes and Hauky, Brit. Moll., vol. iii, p. 248, pi. xciii, fig. 5. 

 1859. Chemnitzia formosa, G. B. Sowerby, 111. Iiid. Brit. Shells, pi. xvi, fig. 6. 

 1892. Chemnitzia formosa, A. Bell, Rep. Yorks. Phil. Soc, pp. 63, 76. 

 1892. Turbouitla formosa. Locard, Coq. mar. Cotes de France, p. 142. 



Specific Characters. — Shell of moderate size, slender, turreted; whorls flattened; 

 ornamented by closely-set straightish costse and by well-marked spiral ridges ; 

 suture oblique, distinctly channelled ; mouth about a sixth of the entire length. 



Dimensions. — L. 8 mm. B. 1"5 mm. 



1 Eep. Brit. Assoc. (Cork), p. 189, 1843. 



