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 
erooves. Silurian and De- 
vonian. Protomya, Hall, is 
similar but without the 
grooves. - 
Leptodomus, M‘Coy, Sil- 
urian ; Elymella, Glossites, 
Euthydesma, Paleanatina, 
and =? Tellinopsis, Hall ; 
Devonian. 
] ao a: ee ; Cardiomorpha, de Kon, 
eee te ee Devonian) ; 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. f 

The Cambrian Fordilla, Barrande, earliest of bivalves if a Mollusk, may possibly belong 
to the Crustaceans near Estheria. 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 within 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 beaks. Silurian and 
Devonian. 

Cardiola, Brod. (Fig. 602): Gloria, Barrande ; Eopteria Fic. 602. 
(? Euchasma), Billings, from the Ordovician, may also belong | Cardiola cornucopiae, 
hoe “ Goldf. Devonian ; Ebers- 
1ere. reuth, Fichtelgebirge. 1/). 
Family 6. Antipleuridae. Neumayr. 
Shell 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), 
Praclucina, Regina, Praelima; to which Neumayr adds Plewrodonta, Conrath, and 
Pararea, Hall. It is possible that Silurina, Barrande, regarded by Neumayr as the 
, 
