112 EOCENE AND LOWER OLIGOCENE CORAL FAUNAS. 



This sj)ecies is represented in tlie collection of the Wagner Institute 

 by ten specimens, including fragments. They were embedded in a glau- 

 conitic sandy clay, and the interior portions have rotted away to such 

 an extent that the details of the sejjta, pali, and columella could not be 

 ascertained as fully as was desired. The generic determination seems cer- 

 tain, and the species is so characteristic that it can be easily i-ecognized. 

 The low costse separate it inmiediately from Carpoj)hyUra dalli, whose costse 

 are very prominent. The septal margins are widely diflterent, as the 

 descriptions of the two species show. The specimen represented in PL IX, 

 fig. 3, is interesting, because it shows apparent reproduction by budding. 

 I was unable to decide whether there was gemmation, or whether one coral 

 had simjjly attached itself to the other for support'; probably the latter 

 is the case. 



Genus STERIPHONOTROCHUS gon. iiov. 



This genus need not be described at length, because a single character 

 s.'parates it from (Jeratotrochus as represented by C. duodecimcostatus. The 

 following description of the type species of the genus, Steriphonotrodms 

 pnlclier s]). nov., will show its external reseniblnnce to C. duodecimcostatns, 

 and the similarity in the character of the columella. The septal marg-ins of 

 Ceratotrochus are entire, without any indication of dentations or crenations, 

 as a careful study of C duodecimcostatus, C. (Conotrochus) tyjms, and C. multi- 

 serialis showed. The septal margins of Steriphonotrochus are regularly 

 crenate (see PI. IX, fig. 5c). 



From the manner of treating the septal margins in the ]:)receding case 

 of Cari/ojjhi/lUa dalll and the succeeding one of Parasmilia ludovlclaiia, it may 

 seem inconsistent to base a genus merely on the character of the septal 

 margins; but in the present instance the conditions are different. There is 

 no indiftei'ent variation from entire margin to crenate margin, l)ut the se})ta 

 of all cycles are regularly uniformly crenate where preserved intact. No 

 other kind of margin is represented. After examining a considerable num- 

 ber of species of Ceratotrochus, and searching carefully in the literature, I 

 have been unable to discover any species that has not simple entire margins. 

 For these reasons it seems to me that the })eculiaritv of the septal margins 

 in Steriphonotrochus is a good Ijasis for generic separation. 



