336 PEOPESSOK P. M. DUNCAN ON THE 



Pourtales, dredged up in 324 fathoms off the Florida reef, is well worthy of study, and 

 has formed part of a late memoir by me to the Eoyal Society'. 



The following species is remarkable, but I cannot place it in any satisfactory 

 position : — 



Genus incertm sedis. 

 . (Plate XLVII. figs. 1-8.) 



'I'he corallum is simple and flat ; the calice is very open, shallow, and irregular, and 

 unsymmetrical in shape, and its margin is broad. 



The costee are large, and irregular in their course and an-angement ; they are in some 

 places straight and subequal, in others curved and unequal ; but all are finely granular 

 and rounded. 



There is no epitheca, no dissepimental tissue ; but there are synapticulse. 



The septa are irregular, rather exsert, in places are thin, alternately large and small, 

 and granular; they pass towards different parts of the centre of the calice. The 

 columella is rudimentary in one portion of the calicular axis, and exists along what 

 appears to be an old line of fracture, which forms a ridge at the base also. There are 

 no pali. 



The specimens appear to have been injured during life and repaired. A smaller 

 specimen, which appears to have been fractured, has grown at the fractured end and 

 developed small septa. 



It is impossible to place these specimens satisfactorily in any genus : they may belong 

 to Diaseris ; but the resemblance of their bases to those of Hemicyathus crassicostatus, 

 Seguenza, Older Pliocene, is most remarkable. The absence of pali, however, prevents 

 the inclusion of the forms in that genus. 



Genus Pliobothrus, Pourtales. 

 Pliobothrus stmmetricus, Pourtales. (Plate XLIX. fig. 7.) 



A specimen of this form was dredged up in the cold area of the North Atlantic, in 

 500 to 600 fathoms. 



I doubt much whether it is one of the Tabulata ; but I introduce it here, and refer to 

 Count Pourtales's description in his ' Deep-Sea Corals,' No. 4 (lUustr. Cat. Museum 

 Harvard Coll. 1871, p. 57) — a most remarkable and interesting work, which, unfor- 

 tunately for me, came to hand many months after the completion of this essay. 



• Phil. Trans. Eoyal Society, 1872. 



