890 Report oF THE STATE GEOLOGIST. 
situated posteriorly, and the transverse band of the ascending 
branches developed into a broad saddle, the posterior margin of 
which incloses the median septum. 
Type, Aingena lima, Defrance (sp.). 
Distribution. Cretaceous. 
Lyra, Cumberland. 1816. 
Synonym; TZerebrirostra, @Orbigny, 1847. 
Plicated shells with the umbo of the pedicle-valve extravagantly 
elongated, terminating in an apical foramen. Deltidial plates 
very large; dental plates highly developed. Loop as in Tzrz- 
Fias.605-608. Lyra Meadi, Cumberland. (Davipson.) 
BRATELLA in immature stages, the connecting lamellz disappearing 
at maturity. 
Type, Lyra Meadi, Cumberland. 
Distribution. Cretaceous. 
Magasella, Dall. 1870. 
Shells exteriorly as in Trresraterta. Brachial valve with a 
highly developed median septum whose anterior extremity is 
elevated and free. Descending branches of the loop attached to 
this septum by broad expansions of the lamellx; ascending 
branches forming a distinct ring, attached at its base to the 
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