Prof. Tennant — South African Diamonds. 



545 



pear to be new, but are not described as new species, partly because 

 the specimens are imperfect, and partly because the living species, 

 with which they could be compared or identified, are still in great 

 confusion, as, for instance, in Dichocoenm, a genus in which the species 

 appear to have been needlessly multiplied. Since the publication of 

 Prof. Duncan's paper two genera, supposed extinct, have been found 

 to be still living in deep water in the West Indies. They are Troelio- 

 cyathus and Antillia. Deep sea-dredging will probably reveal still 

 more. 



Cretaceous. 



Phylloccenia ? j Flabellum ? 



Miocene. 



Placocyathus Barretti, Dune. 



P. eostatus, Dune. 



Platytrochus, or Smilotrochus, spi 



Astrohelia vasconiensis, E. & H-- 



Madrasis decastis, Verrill. 



Stylophora affi'nis, Dune. 



Asterosmilia exarata, Dune. 



A- anomala, Dune. 



A. coronatayDunc. 



Trockosmilia multisinuosa, E. & H. 



Dichoc&nia Slokesi? E. & H. 



P. tuberosa, Dune. 



Tekiophyllia grandis, Dune. 



T. sp. 



Eup hy Ilia,, sp.- 



Antillia bilobata, Dune. 

 Astrocosnia decaphylla, E. & IT. 

 Meandrina labyrinthiformis, Oken. 

 M. sp. 



Piploria cerebriformis, E.& IT. 

 Maricina areolata, Ehrbg. 

 Orbicella cavernosa, Dana. 

 0. endothecala, Dune. sp. 

 Cyphaslrcea, sp. 

 Plesiastrcea ramea, Dune. 

 Siderastrcea galaxea, E. & H. 

 S. siderea, Blanir. 

 Agaricia agaricites-, Irak. 

 Porites fitrcata, Link. 

 Pocillopora crassoramosa, Dune. 



Post-Pliocene. 



Pnehoccenia r S]); 



Stephanoccenia interrupta, E. & H. 

 Eusmillia fastigiala, E. & H. 

 Meandrina strigosa, Dune. 

 Manicina areolata, Ehrbg. 



Colpophyllia gyrosa, E. & H. 

 Orbicella cavernosa, Dana. 

 0. endothecata, Dune. sp. 

 Plesiastrcea ramea, Dune. 

 Porites astrceoides, Lmk. 



V. — Notes on Diamonds from the Cape of Good Hope. 1 

 By Professor Tennant, F.G.S. 



THE first South African diamond was found in March, 1867, and on 

 examining its physical characters, k was pronounced by Dr. 

 Atherstone to be genuine. When this stone was received in London, 

 it created considerable interest, and also some degree of suspicion, 

 some persons having asserted that it was brought forward for mer- 

 cenary purposes ; letters even appeared in the public papers implying 

 that it was impossible it could have been found near Hope Town. 

 As Dr. W. G-. Atherstone, F.Gr.S., of Graham's Town (who in March, 

 1867, examined and pronounced the stone to be a diamond), is now in 

 Bristol, I beg to offer a few general remarks on the Cape diamonds, 

 and also to express in public my thanks to him. 



The late Mr. Mawe, who wrote on diamonds, and described their 

 mode of occurrence in his Travels in Brazil (London, 1812), often 

 expressed to me his opinion of the probability of their existence in 



1 Bead before the Geological Section of the British Association at Bristol, Sep- 

 tember 1st, 1875. 



