TRANSACTIONS OF WAGNER 



' TERTIARY FAUNA OF FLORIDA 



obviously of different function. The genus is a puz/.le and cannot as yet be 

 safely united with any other. Diploschiza Conrad, however, appears to be 

 founded on a broken valve of an ordinary Anotnia. It is impracticable to 

 attempt here a revision or discussion of the names which have been applied 

 to exotic fossils apparently related to this group, as the material is wanting, 

 and few of them have been intelligently studied in the light of the anatomical 

 relations of the recent forms. 



In 1870 Stoliczka (Cret. Pelec. India, p. 451), misled by 'an imperfect 

 knowledge of its synonymic status, proposed for Ephippium (Bolt.) Gray the 

 name Placunema, which falls into synonymy. 



It seems to the writer that the absence of any foramen and the perma- 

 nently byssiferous habit of Placenta generically distinguish it from all the 

 foraminiferous Anomiidce. Its arenaceous habitat is also different from all the 

 rest. 



Placnnanomia as typified by P. Cumingii seems also a good genus. 



The list, omitting doubtful forms and unstudied exotics, will stand about 

 as follows : 



1. Byssal scars absent or obsolete. 



Genus Placenta. Type P. orbicitlaris Retzius. 

 Genus Ephippiitm. Type E. sella Gmelin. 

 Genus Carolia. Type C. placunoidcs Cantraine. 

 Section Wakullina. Type C.Jloridana Dull. 



2. A single conspicuous byssal scar on the disk. 



A. Adult foramen closed ; hinge armate. 

 Genus Placunanomia. Type P. Cumingii Broderip. 



B. Adult foramen small ; hinge unarmed. 

 Genus Pododesmits. Type P. rndis Broderip. 



0. Adult foramen large ; hinge unarmed. 

 Section Monia. Type /-*. macroscliisina Dcshaycs. 



3. Two byssal scars on the disk; hinge unarmed; foramen open. 



A. Main byssal scar largest ; foramen ample. 

 Genus Anomia. Type A. cpliippiitm Linne. 



B. Adductor scar larger than those of the byssus; foramen small. 

 ? Section Patro. Type A. clyras Gray. 



C. Main byssal scar distant from the two others. 

 Section sEnigma. Type A. icnigmatica Jonas. 



