86 FAUNA OF THE CORNBRASH. 



Genus PURPURINA, D'Orbigny. 



This genus was defined by the author in 1850 (' Prodrome,' vol. i, p. 270) 

 as having a " large aperture provided in front only with a very narrow furrow 

 (sillon), which replaces the notch (echancrure) of the Purpura. Columellar border 

 not flattened." He thus included the shells later called Eucyclus, to which, in fact, 

 the majority of the examples quoted below belong. Properly speaking, perhaps 

 this name ought not to supersede D'Orbigny's. But there are certainly two genera 

 included here, which possibly D'Orbigny would have recognised had he lived to 

 write the text on the genus ; and Piette, who constituted Euajdus, restricted Pur- 

 purina to those of which it could be said : " Angular posteriorly, body whorl large, 

 ornamented with longitudinal ribs crossed by spiral stria?." 



Purpurina condensata, Deslongchamps. Plate VIII, figs. 12, lo. 



1860. Purpurina cundcnsata, Deslongchamps, Bull. Soc. Linn. Nurmandie, vol. v, p. 178, pi. i, fig. 8; 



pi. xi, fig. 5. 

 1882. — Hudleston, Geol. Mag. [2], vol. ix, p. 196, pi. v, fig. 3. 



Type, — " A globular shell with a short spire. Whorls strongly rounded, slightly 

 flattened for a certain distance facing the extremity of the spire, thus forming a 

 very obtuse keel. Last whorl very large, with the surface adorned with about a 

 dozen large rounded longitudinal folds, but transversely by very numerous regular 

 small furrows. Mouth elliptical, lips united without a trace of demarcation, forming 

 in front a very broad and very short gutter. Umbilicus small, but quite uncovered. 

 Length 14 mm., length of last whorl 9 mm., breadth 10 mm." 



Description. — Two specimens of this species have been seen, which are almost 

 exact representations of Deslongchamps' figures. The smaller of the two (PL VIII, 

 fig. 12) retains the shell, and shows the young form ; the larger (fig. VS) is a cast 

 only of the variety with coarser spirals, which should be called riblets rather than 

 furrows. These are only feebly indicated. The differences noted are in the pro- 

 portionate size of the last whorl. In our specimens we should not say " very 

 large," for it is a good deal narrower and much shorter in comparison. The state 

 of the apertures preserved does not enable us to verify the existence of a gutter, 

 on which the genus depends. Better specimens alone can decide whether they 

 are Purpurina or not. 



Distribution and Relations. — No others than these two specimens from Scar- 

 borough have been seen, but the species occurs there also in the Kelloway Rock 

 [fide Hudleston). Though these specimens have been called Turbo elaboratus, they 



