36 BRITISH FOSSIL CORALS 



The species of tlie genus Sjiiilotrochus from the Gault are as fohows : 



1. Smilotrochus elongatus, Duncan. 



cylindricus, „ 

 granulatus, „ 

 „ insignis, „ 



\. Smilotrochus elongatus, Duncan. PI. XII, figs. 10 — 16; PI. XIII, figs. 10 — 12; 



and PL XIV, figs. 13—15. 



This species is described at page 19 of the first number of this Part, and is figured in 

 PI. VII, figs. 1—6. 



Locality. Folkestone, In the Collection of the Royal School of Mines. 



The lateral spines of the septa are very well marked, and the costee are equal in size in 

 this species. Its septal number varies, on account of the very late perfection of the fourth 

 cycle of septa. 



•J. Smilotrochus cylindricus, Duncan. PL XIV, fig. IG. 



The corallum is small, cylindrical, nearly straight, and has a truncated base. 



The costae are equal, very distinct above, and rudimentary below and in the middle. 

 They are marked with a few large granules in one series. 



The septa are subequal, very exsert, thin, close, and marked with large granules, 

 few in number. The septa are in six systems, and there are three cycles. 



Height, -njths inch. Greatest breadth, rather less than i^ths inch. 



Locality. Gault, Folkestone. In the Collection of the Rev. T. Wiltshire, F.G.S. 



3. Smilotrochus granulatus, Duncan. PL XIV, fig. 17. 



The corallum is conico-cylindrical in shape, and has a more or less truncated base. 

 The costse are subequal, prominent, very granular, and distinct superiorly. 

 The septa are subequal, thick, and very granular. The septa are in six systems, and 

 there are three cycles. 



Height, i^ths inch. Breadth, ^-ths inch. 



Locality. Gault, Folkestone. In the Collection of the Rev. T. Wiltshire, F.G.S. 



