FROM THE UPPER GREENSAND. 



Genus — Smilotrochus, Ed. and H. 



The corallum is simple, straight, cuneiform, free, and without a trace of former 

 adhesion. There is no columella. 

 The wall is naked and costulate. 

 There is no epitheca. 

 The simple costse are distinct from the base to the calice. 



This is the simplest form of Agarose Zoantharia, and its structures only comprise a 

 ■wall, septa, and costse. Flabellmi has an epitheca in addition, and Styloirochus of De 

 Fromentel is a Smilotrochus with a styliform columella, the septa uniting also by their 

 thickened internal margins. OncJiotrochis, nobis, has a pellicular epitheca, no columella ; 

 but, like Styloirochus, the septa are united internally. 



1. Smilotrochus tuberosus, Bd. and H. 



Teoohosmilia tuberosa, Ed. and H. 

 TURBINOLIA COMPRESSA (?), Morris. 



This species, with five cycles of septa, was described in the ' Monograph of the Brit. 

 Foss. Corals, Upper Greensand,' Milne-Edwards and Jules Haime. 



2. Smilotrochus Austeni, Ed. and H. PI. VII, fig. 12. 



This species is thus described in the ' Hist. Nat. des Corall.,' vol. ii, p. 71 : 

 The corallum is regularly cuneiform, very much compressed below, and slightly elongate. 

 The calice is elliptical ; the summit of the larger axis is rounded. 

 Forty-eight costse, subeqaal, straight, fine, and granular. 

 Height of the corallum, about ^rd inch. 

 Locality. Farringdon. 



MM. Milne-Edwards and Jules Haime do not mention where the specimen is 

 deposited. 



3. Smilotrochus elongatus, Duncan. PI. VII, figs. 1 — C. 



The corallum is tall, straight, and nearly cylindrical. 



The columellary space is large. 



The septa are fine and unequal, especially in length. There are four cycles of septa. 



Height, about an inch. 



