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MONOGRAPH 



FORAMINIFERA OF THE CRAG. 



Class — RHIZOPODA. 

 Order-RETICULARIA (FORAMINIFERA). 



^v2.-oRO¥.Yi—IMPEBFOBATA. 



Family— MILIOLIDA, Carpenter. 



Genus — Corxuspira, Schultze. 



Orbis, Philippi (in part). 



CoRNUSPiRA, Schultze (in part). 



Spikillina, Williamson (in part). 



SoLDANiA, D'Orbigny (in part). 



Opeeculina, Czjzek and Reuss (in part).i 



CoRNUSPiRA, Parker and Jones, Carpenter, Reuss, Brady. 



General characters. — Shell, a flat spire, formed of a simple, non-segmented, and 

 usually unconstricted tube, coiled on itself in a horizontal plane, usually cylindrical in 

 the earlier portions of its growth, but becoming wider and flatter as it approaches 

 maturity : white, opake, smooth, and free from ornamentation or surface- markings, 

 except slight transverse ridges, apparently indicating its successive additions during growth. 

 Aperture, terminal ; oval or slit-Uke in shape, according to the extent of flattening which 

 has taken place in the tube. 



D'Orbigny, in the ' Annales des Sciences NatureUes,' vol. vii, p. 281, grouped a number 

 of complanate Poraminifera under the generic name Soldania. The figures in Soldani's 



1 Operculina cretacea, Reuss, Verst. bdlim. Kreid., p. 35, pi. 13, figs. 64 and 65 {Cornuspira 

 cretacea, Reuss, Sitzungsb. K. Ak. Wien., vol. xl, p. 177, pi. 1, fig. 1), seems to be the same as D'Orbigny's 

 Operculina incerta, Foram. Cuba, p. 49, pi. 6, figs. 16, 17; and this is a Trochammina. 



