424 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 6, 



Dimensions. — Diameter of the corallites from 1 line to 2 lines ; 

 height several inches. 



This species of Stephanocoenia differs widely from the form from San 

 Domingo ; and its distinct, thin, linear pall distinguish it from all 

 others. It has no other than a generic affinity with the depicted, but 

 not described, Steplianoccenia tenuisepta of the late M. Haime. 



From the Inclined Beds and the Chert of Antigua. Coll. Geol. Soc. 



14. M^EANDRINA, Sp. 



One specimen from the lower formation of Antigua is a semi- 

 polished silicified fossil, greatly affected by the destructive form of 

 silicification. A few transverse views of " series " enable me to 

 classify it with the Mceandrince, but it presents structural peculiarities 

 which remove it from the recent forms and connect it with those 

 described as fossil. It does not come within the diagnosis of any 

 species as yet described. 



Valleys moderately long, very flexuous, repeatedly branching at 

 nearly right angles. Columella sublamellar, deficient here and there 

 for a very slight interval. Septa alternately large and small, the first 

 extending close to the columella, presenting occasionally a slight 

 transverse enlargement at the end ; all delicate and straight, there 

 being seven in a length of 1 line. Mural elevations (collines) small 

 and delicate. Breadth of the valleys T \j inch. 



The recent Mceandrince have a well-developed spongy columella, 

 but in the fossil forms that organ has a lamellar structure and is 

 more or less defective. The breadth of the valleys is, as a rule, 

 smaller in the fossil than in the recent species. 



From the defective state of the fossil above described (Coll. Geol. 

 Soc), no specific determination is possible, but its characters relate 

 to fossil more than to recent forms. 



15. Cosloria dens-elephantis, spec. nov. PL XIV. fig. 8. 



Valleys long, very much disposed to be nearly straight, branching 

 rarely, and then at an acute angle, parallel, varying greatly in 

 width. The resemblance of transverse sections to the dental laminae 

 of Eleplias is most remarkable. Length 1 inch ; breadth from 2 

 to 3 lines. A columella is present as a few laminae, occasionally 

 continuous with the septa. Septa alternately thick and thin, with- 

 out pali or transverse enlargement, four or five to y 1 ^- inch. Endo- 

 theca abundant and at right angles to the septa. The mural eleva- 

 tions, so far as can be judged from a section, are small and delicate. 



The specimen is an example of the variety of siliceous fossilization 

 where the interspaces are filled with porcellanous and opaline silica, 

 the sclerenchyma having lost much of its details and being turned 

 into homogeneous dark flint. 



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



16. Astroria polygonalis, spec, nov.* PI. XIV. fig. 6. 



Walls bearing a very small proportion to the size of the corallite (in 

 * In the Hist. Nat. des Corall., by Edwards and Haime, the genus Coeloria 



