1863.] DUNCAN WEST INDIAN CORALS. 431 



and render the intervals between them delicate and linear. Each 

 costa consists of alternate granular swellings and linear intervals, 

 being thus irregularly moniliform. The smaller costae present 

 smaller granulations. Intercostal dissepiments wanting. Calice 

 elliptical, margin broad, fossa very deep. Length to breadth as 

 16 to 10. Length | inch and -j- - ; breadth -J- inch. Depth of fossa 

 2 lines. Marginal surface on one plane. Septa well developed, 

 projecting upwards three-quarters of a line, boldly arched above, 

 ending in costae externally, but arched and irregularly prominent in 

 the fossa internally. They slope at last to the bottom. All the 

 septa have more or less a tendency to radiate from the eroded end. 

 Primary and secondary septa very much alike ; the others are un- 

 equal, according to their orders, but the tertiary are a little smaller 

 than the secondary. Free septal margin strongly and regularly 

 granulated ; sides of the laminae marked with rows of granulations 

 with sharp points, each row ending at the septal margin in one of 

 the swellings. Granulations very distinct on broken septa. No pali, 

 endotheca, nor synapticulae. Septa in six systems of five cycles ; in 

 all ninety-six septa. Columella badly developed, parietal, consisting 

 of a lax tissue reaching from the septa to those on each side ; it is 

 situated at the bottom of the fossa. 



The species under examination is one of the Turbinolides, as 

 there are no pali ; it is deficient in endotheca, open from the base of 

 the fossa upwards, and has a dense wall ; the epitheca is tolerably 

 developed. Coming thus under the division of epithecal Turbino- 

 lides, it is associated with Flabellum, Rhizotrochus, Placotrochus, and 

 Blastotrochus. 



Blastotrochus is distinguished from the other genera by its gem- 

 miparous reproduction ; it is moreover cylindroid. Placotrochus has 

 a laminar columella. Flabellum has non-projecting septa, and costae 

 crested, spined, and covered by epitheca. This last genus only re- 

 sembles the new form in its species having more or less granular 

 septa, a parietal and badly developed columella, and a high septal 

 number. The elliptical calice of Rhizotrochus, as well as the arched 

 and prominent septa and deep fossa of that genus, are found in the 

 new form. Allied thus to Flabellum and Rhizotrochus, the genus 

 Thysanus is distinguished by its lateral erosion, highly granular 

 costae, incomplete epitheca, grooved base, and elliptical and depressed 

 shape. 



From the Mvaje shale. Coll. Geol. Soc. 



8. Barysmilia intermedia, spec. nov. PI. XY. fig. 4. 



Corallum with the trunk irregularly cylindrical, the spot of former 

 adhesion being smaller than the diameter of the trunk, which has 

 some undeveloped calices on its surface. Head convex and closely 

 covered with calices, whose long axis is in no definite direction. 

 Calices crowded, tolerably elevated above the surface, elliptical and 

 circular, forming series of not more than three, by fissiparity ; lateral 

 margin of some calices higher than others. Fossa tolerably deep. 

 Septa barely exsert, slightly arched inwards, granular on their faces ; 



