56 BRITISH FOSSIL CORALS. 
The calice is unsymmetrical, from its peculiar septal arrangement; its marginal wall 
is very thin, and the fossa is deep. ‘The columella is angular in its transverse outline, 
and is often very prominent. 
The septa are unequal, straight, and delicate. There are no septa corresponding with 
the rudimentary cost ; their arrangement gives the idea of there being two systems of 
three cycles, the septa of the third cycle being deficient; but there are really six 
systems. 
In four systems there are three cycles of septa, and the rudimentary costz are of the 
fourth and fifth orders; and in the remaining systems there are two cycles of septa with 
the rudimentary costz of the third order. 
Height of corallum 2ths mch. Diameter of the calice 3th inch. 
The cyclical arrangement and the rudimentary costz distinguish this species from all 
the others. 
Locality. igh Cliff, Isle of Wight. In the collection of Frederick Edwards, Esq., 
F.G.S. 
The genus Zurbinolia, thus enriched by the discovery of three new species, was so 
elaborately described by MM. Milne-Edwards and J. Haime, that it only remains to place 
these species in their proper position in the genus. 
The following scheme will point out their correct affinities : 
TURBINOLIA. 
TURBINOLI® with four cycles of septa; the fourth more or less incomplete. Turbinolia costata. ie 
” » » ” ” » = dispar. 2: 
— *evaratal oe 
— *Dizoni. 4. 
URLs 5. 
— *afinis. 6. 
= three cycles of septa : . — Pharetra. "E 
= laminifera. 8. 
— Nystana. 9. 
— attenuata. 10. 
= pygmea. ll. 
— *sulcata. U2 
; — *Bowerbanki. 13. 
three cycles of septa, with coste of a fourth cycle aa _ eRpeden ee 
| — *Prestwichi. V5: 
— ‘*minor. 16. 
4s three incomplete cycles of septa : — *Forbesi. We 
| — *humilis. 18. 
* The species marked with an asterisk are British. 
Turbinolia attenuata, Keferst. ¢ These species require further examination ; they were discovered 
—  laminifera, Keferst. in the “ Unter-Oligocan ’’ of Germany, are very minute forms, 
—  pygmea, Roemer. and are probably the young of other species. 
