TERTIARY CORALS. 55 



2. TuRBiNOLiA EXARATA, Duncan. Plate IX, figs. 4, 5, 6, 7. 



The corallum is conical inferiorly and cylindrical superiorly, so as to be rather sub- 

 turbinate. Its base is small and narrow, although the costse are very projecting there. 



The costse are greatly developed ; they are subequal, very prominent, and thin ; their 

 free margin is rather sharp, and not much narrower than their base. 



The largest costse are very prominent inferiorly, and the tertiary arise at the distance 

 of about one quarter of the whole height of the corallum from the base. 



The costse are very wide apart, and the base or bottom of the intercostal spaces is 

 wide, very visible, and it is not marked by any dimpling. 



The sides of the costse are strongly marked with a rudimentary exotheca, which is 

 attached to the wall close to the base of the costse (fig. 7). 



The wall is very thin. 



The calice is circular in outline, very deep, and its margin is rendered very distinct by 

 the well-developed costse. 



The septa are slender, thin, and unequal ; they form three perfect cycles, and there are 

 six systems. 



The septa and costse correspond. 



The columella is very small, cylindrical, pointed, and in the typical specimen there are 

 two papillse on its free surface. 



Height ~ths inch. Diameter of the calice ^ths inch. 



This very interesting species resembles the Turbinolia PrestwicM, Edwards and 

 Haime, in some points ; but it has no vestige of a fourth cycle of costse ; moreover, the 

 new species has not the truncated base of Turbinolia PrestwicM, and its third cycle of 

 costse arise high up. 



The width of the intercostal furrows and the absence of well-marked dimpling are 

 very distinctive peculiarities of Turbinolia ewarata. 



Locality/. — The species is found at Brook, Hampshire (New Forest). In the collection 

 of Frederick Edwards, Esq., E.G.S. 



3. Turbinolia Eorbesi, Duncan. Plate IX, figs. 8, 9, 10, 11. 



The corallum is very small, conico-cylindrical, and has rather a sharp base. 



The costse are very stout, obtuse, and slightly prominent; the largest are often wavy 

 in their upward course, and all are separated by wide intercostal furrows or spaces. There 

 is a well-marked but very small costa situated high up in the corallum and in each 

 intercostal space. 



There ai-e large and distinct exothecal markings on the sides of the costse ; but the 

 existence of dimples on the wall at the bottom of the intercostal spaces is too doubtful to 

 be safely asserted. 



