334 071 a new Genus of Palceozoic Corals. 



disposed to place these corals under the genus Petraia but 

 for two facts. In the first place, the septa appear to be 

 clearly arranged in multiples of six, being twelve at the base 

 and eighteen in number at the calice ; whilst, in the second 

 place, there is the anomalous character that the extreme base 

 of the corallum is destitute of an epitheca. The visceral 

 chamber is thus open below as well as above, the inferior 

 aperture being distinctly circumscribed, circular in form, and 

 exposing to view the slightly exsert septa. At first sight I 

 thought this aperture might perhaps be accidental ; but it is 

 present in all the specimens I have examined, with the excep- 

 tion of one large example, in which it appears to have been 

 cicatrized, and is only obscurely and with difficulty recog- 

 nizable. From the cyathophylloid corals Diincanella is 



DtmcaneUa horealis, Nicli. : a, side view of an average specimen, of the 

 natural size ; b, vertical section, showing the very deep cylindroid 

 calice ; c, transverse section, enlarged ; f/, side view of the base, en- 

 larged, showing the inferior aperture and slightly exsert septa ; e, the 

 base viewed from below, much enlarged, showing the absence of the 

 epitheca and the septa meeting in a central point. 



distinguished by not having the septa in multiples of four, 

 and by the total absence of tabulas or dissepiments. From 

 Cyathaxoniaj lastly, the present genus is distinguished by its 

 want of a columella and septal fossette, the number of the 

 septa, and the characters of the base. 



The following is the only species of the genus that has come 

 under my notice : — 



Duncanella horealis (Nicholson). 



Corallum simple, free, cylindro-conic, from 7 to 10 lines in 

 length, and 2 lines in diameter at the calice. The base is 

 truncated, destitute of an epitheca, and exhibiting a circular 

 opening about half a line in diameter. Within this opening 

 are seen twelve septa which extend from the circumference to 

 the centre, and usually project slightly in the form of a little 

 cone. The rest of the coral is covered with a well-developed 

 epitheca, which exhibits well-marked longitudinal ridges, 

 together with a few shallow annulations of growth, between 



