362 



MOLLUSCA 



SUB- KINGDOM VI 



Grammysia, Vern. (Sphenomya, Hall), (Fig. 601)* Shell elongate-ovate, concen- 

 trically sculptured, with a deep lunule ; cardinal margin thickened, edentulous ; 



surface with several radial 

 grooves. Silurian and De- 

 vonian. Protomya, Hall, is 

 similar but without the 

 grooves. 



Leptodomus, M'Coy, Sil- 

 urian ; Elymella, Glossites, 

 Euthydesma, Paleanatiiw , 

 and ? Tellinopsis, Hall ; 

 Devonian. 



Cardiomorpha, de Kon. 



Grammysia HumiUoneim$,Verii. Spirifer Sandstone (Lower Devonian) ; ^ , a , i , > -, 

 Lahnstein, Nassau (after Sandberger). Oval, inflated, beaks almost 



anterior, conspicuous, ad- 

 jacent, prosogyrous ; hinge line thin, arched. Silurian and Carboniferous. 



Isoculia, M'Coy. Like the preceding, but with coarse concentric sculpture. 

 Carboniferous. 



Other Carboniferous genera are Broeckia, de Kon.; Chaenomya, Meek; Sedgwickia, 

 M'Coy ; and Edmondia, de Kon. The last is like Cardiomorpha, but gapes in front, 

 with a narrow ridge below the beaks. 



The Cambrian Fordilla, Barrande, earliest of bivalves if a Mollusk, may possibly belong 

 to the Crustaceans near Esthcria. It is minute, oval, somewhat arcuate, and concentrically 

 striated. Potsdam. 



What appears to be a genuine Pelecypod, and so far the only one except Fordilla which is 

 known from the Cambrian rocks, is Modioloides priscus, Walcott. It 

 is transversely oval, with sub-central, incurved beaks, and an anterior 

 adductor scar visible Avithin an apparently simple pallial line. It is 

 minute (2 mm. long), and known by an internal cast from the Lower 

 Cambrian of Washington County, New York. The Ordovician 

 Redonia, Rouault, is not dissimilar. 



Family 5. Cardiolidae. Neumayr. 



Shell equivalve, inflated, obliquely ovate, with prominent beaks, 

 and edentulous hinge ; sculpture often radial, or sometimes of con- 

 centric ridges, which may be confined to the leaks. Silurian and 

 Devonian. 



Cardiola, Brod. (Fig. 602) : Gloria, Barrande ; Eopteria 

 (? Euchasma), Billings, from the Ordovician, may also belong 

 here. 



FIG. 60-2. 



Cardiola cornucopiac, 

 Goldf. Devonian ; Ebers- 

 reuth, Fichtelgebirge. a /i- 



Family 6. Antipleuridae. Neumayr. 



SJiett very inequivalve, without gape below the beaks ; hinge obscurely Taxodont, with an 

 amphidetic area and predominantly radial sculpture. Silurian. 

 Antipleura, Dualina, and Dalila of Barrande. 



Family 7. Praecardiidae. Neumayr. 



Shell equivalve with Taxodont dentition and usually strong radial sculpture. Silurian 

 and Devonian. 



This family contains the following genera of Barrande from the Silurian of 

 Bohemia : Praecardium, Paracardium, Puella, Pentata, Buchiola (Glyptocardia, Hall), 

 Praelucina, Regina, Praelima ; to which Neumayr adds Pleurodonta, Conrath, and 

 Panrarca, Hall. It is possible that Silurina, Barrande, regarded by Neumayr as the 



