MAWYLWI) ril'.ol.OdlCAI, sritVKY ii-) 



tcriiil t(i (Irlci'iiiiiic llic \;iliic nf this fcal iii'c. 7'. irn iil iihhrciiNls is the 

 more rol)iist species, 7'. ncii/irdsluhi is mure slendei". The l;ist meii- 

 liniicil (liU'cronee is the most si I'ikiiiii' one Tl is exlreiiu'ly pr()])!il)le 

 th;lt T. iniii/iihhrriisis is ;i dirrct (h'sccii(hliit fi-olii 7'. aridicoslaln . 



7'. jilidri'lrd \A'i\ also possesses a colnmcna with a hiv\a,Li'oiial iippiT Iit- 

 miiiatioii. It (h)rs not possess rudimentary costae, and the costae have 

 entire ed^es, l»iil it and the two above diseussed species are very closely 

 related and probably should he grouped in a section or subgenus of 

 Tiirhi iiolid. 



Orntrrencc. — XAX.Tic^roY Fokmatiox. Popes Creek. Aqtfa Foiorv- 

 Tiox. Potomac Creek. 



CoUcdions. — Johns Hopkins University, Maryland Geolo<iical Survey. 



Family CARYOPHYLLIDAE. 



Genus TROCHOCYATHUS Milne-Edwards and Haime. 



Trochocyathus clarkeanus Vaughan, 



Plate LXI, Figs. 5, 5a, 6, 7, 8. 



FaracyathuK (?) clarkeanus Yauglian, 18V)5, Johns Hopkins Univ. Circ, vol. xv, p. (5. 

 Paracuathus (?) clarkeanus Yaughan, 1896, Bull. No. 141, U. S. Geol. Survey, p. 89. 

 Trocfiocyathus chn-keaims Vaughan, 1900, Mon. U. S. Geol. Survey, No. 39, p. lOO, 

 pi. vii, flgs. 20-23. 



Descriplioii. — "Coralhim conical, usually sliybtly curved. Cross-section 

 elliptical. ISTearly always showing a distinct area of attachment, which 

 is variable in size. Costae not very prominent; acute; 48 in number, 

 corresponding to all the cycles of the septa; nearly equal in size. In 

 young specimens those corresponding to the last cycle of septa are 

 smaller than those earlier developed. No epitheca was observed and is 

 most probably absent. Septa thin, not exsert, sides granulated; 48 in 

 number, arranged in six systems of four cycles each; those of the first 

 three cycles reach the columella: the fourth cycle fuse by their inner 

 margins to the sides of the third cycle. Calicular fossa shallow. Pali 

 apparently before all of the cycles of the septa except the last, small 

 and thin, and appear to be arranged in two crowns. Eudimentary dis- 

 sepiments apparently present. Columella fascicular; upper surface 

 papillate." Vaughan. 1900. 



15 



