Vol. 56.] FOSSIL CORALS AND ECHINIDS OF SOMALILAND. 



39 



Type-species. — Turbinacis erytliroeensis, sp. nov. Pleistocene: 

 Somaliland. 



Affinities. — This genns has the habit of a Stylophora, the 

 numerous subequal septa of a Turbiuaria, and the calices of an 

 Actinacis. It is most closely allied to the last-named genus, from 

 which it differs by the absence of pali, the more scanty coenenchyma, 

 and the more numerous septa. It differs from Astrceopora, whicli it 

 resembles in the character of the coenenchyma, by the presence of a 

 prominent, well- developed columella. From Turbiuaria it differs 

 by its arborescent habit, the more scanty coenenchyma and the 

 prominence of the primary septa in younger calices. 



Turbo-acts ertthr^ibn-sis, 1 sp. nov. (Text-figs. 3 a & 3b.) 



Diagnosis. — Corallum of slender, cylindrical, dichotomous 

 branches. Coenenchyma very variable in width, ranging from a 

 thin band, nearly equal in width to the calices, till it is practically 

 absent. Externally the coenenchyma appears porous, as it is pierced 

 by numerous circular punctations. 



Septa in young calices six in number, and prominent ; in older 

 corallites the number of septa increases, and they fuse into groups 



Fig. 3. — Turbinacis erythraeensis, gen. et sp. nov. 



a. X 6 diai 



b. X 7 ctiatu. 



a — Part of the surface of the corallum. 



b — Part of a transverse section of the same. 



of six, which resemble six thick primary septa. In the mature 

 corallites the number is about thirty, and they are ail subequal. 

 Columella large, often hollow ; sometimes it appears styliform. 



Dimensions. — Diameter of branch: 

 width of coenenchyma = # 2 to '} 



mm, 



Distribution. — Pleistocene : raised 



= 10 mm.; 

 mm. 

 reefs, near 



of calices = 



Berbera, So- 



maliland. Coll. Capt. E. T. Marshall. 



1 From Mare Erythrceum, the Red Sea. 



