FROM THE GAULT. 37 



4. Smilotrochus insignis, Buncan. PL XII, fig. 17 ; and PI. XIV, fig. 18. 



The corallum is trochoid, short, and has a wide caHce, and a conical and rounded 

 base. 



The calice is circular in outline ; the fossa is deep and small, and the septa are wide, 

 exsert, curved above, and so marked with one row of granules that their free margin 

 appears to be spined. There are three cycles of septa, and the orders are nearly equal as 

 regards size. 



The costse are large, prominent, broad at their base, and are marked with one row of 

 granules on the free surface. 



Height, i^ths inch. Breadth of calice, i^ths inch. 



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



An analysis of the genus will be found after the description of the species from the 

 Lower Greensand. 



There is a compound or aggregate Madreporarian found in the Gault of Folkestone. 

 It has much endotheca, and resembles worn specimens of the well-known Holocystk 

 elegans of the Lower Greensand. The specimens are not sufficiently well preserved for 

 indentification with any genus. 



i^««2«7j/— FUNGIBLE. 

 Sub-family — Fungin^. 

 Genus — Micrabacia. 

 1. Micrabacia Fittoni, Duncan. PI. XIV, figs. 6 — 9. 



The corallum is nearly hemispherical in shape. Its base is flat, aud extends beyond 

 the origin of the septa in a sharp and uninverted margin. The breadth of the base exceeds 

 the height of the corallum. 



The costae are flat, straight, convex externally at the calicular margin, and equal. 



The septa are unequal, much smaller than the costse. There are four cycles of septa, 

 in six systems. 



The synapticulse between the septa are large. 



Height, -j^ths. Breadth, nearly \ inch. 



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



