The Invertebrate Fauna of the Uitenhage Series. 169 



is bounded above and below by a prominent longitudinal (spiral) 

 keel ; these two principal keels are of equal strength, and while the 

 lower one is smooth (or nearly so), the upper one is bluntly nodular. 

 Each of the rounded nodes of this keel is prolonged in wedge shape 

 downwards into the marginal band, but the apices of the wedges die 

 out before they reach the lower keel. At the end of the fourth 

 whorl the wedge-like ornaments appear to be losing the well-defined 

 character they possessed at the beginning of this whorl and before, 

 while early in the fourth whorl an intermediate (central) peripheral 

 keel makes its appearance, though it is less strongly developed than 

 the two pre-existing marginal keels. 



Below T the marginal band the surface of the body- whorl has an 

 evenly rounded outline ; it is ornamented by three prominent spiral 

 keels, one situated near the lower marginal keel and almost as 

 strongly developed as this, the other two, rather weaker, below and 

 in close proximity to one another. The spiral angle is about 70. 

 The spiral suture is immediately under the lower marginal keel. 

 The mouth aperture has equal breadth and height. The outer lip is 

 sharp and thin and slightly angular, in accordance with the form of 

 the whorl. The inner lip is slightly thickened. 



Dimensions. 



Height of specimen with four complete whorls 8 mm. 



Greatest diameter of the last whorl 6 , , 



Height of aperture 4 ,, 



Occurrence. Cliff below the old school-house at Dunbrodie, on the 

 right bank of Sunday's Eiver (305, 351). 



Remarks. This form, though apparently a near ally of Turbo 

 atherstoni and T. rogersi, is readily separable from these by the 

 regular nodose ornaments on the upper marginal keel and peripheral 

 zone below this, as well as by the stronger development and smaller 

 number of the spiral keels on the under surface of the whorl, below 

 the lower marginal keel. It seems probable that this shell would 

 attain dimensions as large as those reached by T. atherstoni, and the 

 appearance of a central marginal keel in the last whorl of the largest 

 individual examined very strongly recalls the increase of the spiral 

 ornaments in the associated forms mentioned. 



TUKBO sp. 



An imperfect specimen, consisting of a body- whorl deprived of the 

 spire, may be provisionally referred to this genus. The greatest 

 breadth across the base is 8 mm., and the diameter of the mouth 

 aperture which is nearly circular, measures 4 mm. The surface is 



