62 BRITISH POSSIL CORALS. 



costae arc granular either in series of one or of two rows, whilst the lower present many 

 irregular rows. The cross bars of the exotheca are numerous. 



Height of corallum 2 inches. Diameter of calice f'„ths inch. 



LocaJiii). — Bracklesham. In the Dixon Collection in the British Museum. 



This species, very closely allied to D. dendrophyUoidcs, is distinguished from it by the 

 habit of growth, by there being multi-granulose costa;, and by the development of the 

 higher orders of the septa. 



Smno^—3IADBEP OB Alii A PEBFOBJTA. 

 Family— MADREPORIDiE. 



Sub-family — Turbinarin^. 

 Genus — Dendracis. 



Dendracis — generic characters.^ 



Corallum arborescent ; coenenchyma very dense, granulated on the surface ; calices 

 siibmammiform ; no columella; septa few in number and barely exsert. 



Dendracis Lonsdalei, Duncan. Plate X, figs. 11 — 14. 



The corallum consists of stems branching laterally, both the stems and branches 

 being nearly cylindrical. 



The coenenchyma is very abundant, is covered with blunt conical dentations, and the 

 calices are rare, but slightly elevated, and very small. The calices seem to be defects 

 in the ccenenchyma rather than independent structures. They are wide apart, circular, 

 shallow, and have no columella. The septa are twelve in number, very large at the 

 margin, and every other one has a thin continuation which passes inwards. The central 

 space is deep. There are no costae (fig. 12). 



The transverse section of a stem shows its cellular nature, and that it consists of 

 superimposed coenenchymal cells (fig. 13). 



Diameter of stems j^ths inch. Diameter of calices ,„th inch. 



LocaUty. Bracklesham. In the Dixon Collection in the British Museum. 



The wide apart and rare calices, and the strongly echino-deutate coenenchyma, dis- 

 tinguish this species from the Dendracis Gervillii, Defrance, sp. 



The new species is attached to the under part of the base of Lonsdale's typical 

 specimen oi Porites panicea described in Dixon's ' Geology of Sussex' (pi. i, fig. 7). 



1 'Hist. Nat. des Corall.,' vol. iii, p. 1G9. 



