1863.] DUNCAN WEST INDIAN COKALS. 425 



transverse section). Calices polygonal, varying in size ; many form 

 short series, but the simple corallite is in excess. Columella very 

 rudimentary. Septa long, thin, alternately large and small ; they 

 are generally numerous, but in a small corallite they are few, and 

 resemble those of an Astrcea with a low septal number. A small un- 

 developed corallite gives six systems, two cycles in some and three 

 in other systems. Length of each series 9-Jr lines ; three septa to 

 -jlj inch ; the width varies, from the ends of the series being pointed. 

 Width of the largest corallites not forming series | inch, of the 

 smallest -J- inch. Endotheca abundant and subvesicular. 



From the Chert-formation of Antigua. Coll. Geol. Soc. 



The lithological character of this specimen is very interesting, the 

 interspaces being filled with opalescent and opaque-white silica. 



17. Astroria afeinis, spec. nov. 



Corallites crowded. "Walls very thin indeed. Transverse section 

 of corallites polygonal, rarely forming short series. Columella slightly 

 but decidedly developed. Septa alternately large and very small, 

 linear, a little larger externally, with at least four cycles in six 

 systems. Breadth of the calices 4 lines ; five septa to 1 line. Endo- 

 theca abundant. 



From the Chert-formation of Antigua. Coll. Geol. Soc. 



The greater independence of the calices and the rare fissiparity 

 connect this species very closely with the Astraeans. In some parti- 

 culars it is allied to A. astrceiforrnis (a recent species inhabiting the 

 Red Sea) ; but that species has a rudimentary columella, only three 

 cycles of septa, and smaller corallites. It has greater affinities with 

 the species of Astroria just described than with any recent form. 



18. Astroria Antigtjensis, spec. nov. 



Corallites not crowded, but close, tall. Walls rather thin. The 

 transverse section of the corallites is in many cases circular, in others 

 obscurely polygonal; some present short series, but rarely. Columella 

 very indistinct. Septa alternately large and small, in six systems of 

 four cycles, the fourth being occasionally deficient in two systems. 

 Breadth of the corallites from 2 to 3-|- lines. Length of the series 

 6 lines ; five septa to a line. Endotheca abundant. 



Eossilization like that of the other Astrorians, and rendering the 

 details indistinct. It is closely allied to the other species of Astroria 

 from Antigua. 



Erom the Chert-formation of Antigua. Coll. Geol. Soc. 



19. Astroggenia ornata, Edwards & Haime. PL XIV. fig. 7. 



This well-known Miocene species is found in the Chert-formation 

 of Antigua. The corallum is massive, in some cases most singularly 

 altered by fossilization, and presenting most abundant corallites ; the 



absorbs Astroria (see vol. ii. p. 412). I have, however, retained the latter as a 

 distinct genus, as it certainly forms a connective link between the fissiparous 

 AstrcecB and the Coelorice, and a certain number of species group themselves 

 readily within the terms of its definition. 



VOL. XIX. PART I. 2 G 



