DESCRIPTIONS OF SPECIES. 



75 



1850. PlatytroeJms stol-esii d'Orbigny. Prodr. de Pal., 6tage 25, num. 1245. 



1851. Platyirovhus stokesii Milue-Edwards aud Haime. Polyp, toss, des Tei-r. Pal., 



p. 29. 

 1857. Platytrochm stokesii Milne-Edwards and Haime. Hist. Nat. des Corall.,Vol. II, 



p. 72. 

 1861. Platytrochus stokesii de Fromentel. Introd. a I'fitude des Polyp, foss., p. 93. 

 1860. Platytrochus stokesii Conrad. Check List, p. 2. 

 1881. Platytrochus stokesii Quenstedt. Kohren- u. Sternkorallen, p. 941, pi. clxxis, 



fig. 75. 

 1886. Platytrochus stokesii Aldricb. Prelim. Rept. on Tert. Foss. of Miss, and Ala., 



p. 49. 

 1886. Platytrochus stokesii Meyer and Aldricb. Jour. Cincinnati Soc. Nat. Hist., Vol. 



IX, No. 2, p. 50. 

 1890. Platytrochus stokesii de Gregorio. Mon. de la Fauue ^ocenique de I'Ala., p. 254, 



pi. xlv, figs. 1-14. 



Shape short cuneate, transverse outline elhptical, base emarginate. 

 Costfe 24, corresponding to all of the septa. The nine costse on the middle 

 portion of a face converge toward the base, and become narrower as the 

 base is approached; the marginal costse, i. e., those at the ends of the longer 

 transverse axis, and those standing immediately next them, become wider 

 toward the base. The costse next the marginal ones are the larger, and are 

 very much expanded inferiorly. All of the costse are gi'anular; the seven 

 in the middle of a face begin as a single row of granules; they later 

 become tlu-ee granules alongside one another. The eight intercostal 

 furrows on the middle portion of a face are nearly straight; the furrows 

 immediately outside of those do not converge uniformly toward the base, 

 but near the basal end of the corallum usually bend outward. Septa 24, 

 three cycles. Those of the first and second cycle meet the columella. 

 The septa of third cycle fuse by their inner margins to the sides of those 

 of the first. The surface beset with sharp granules. The upper margins 

 of the septa crenate-dentate and the inner portions undulated. No true 

 pali present. Columella described in discussing the genus. 



