Foraminiferal Limestones. 227 



This yellow limestone is composed largely of foraminifera ; and, 

 besides these, it contains polyzoa and Lithothamnion, both branching 

 and massive. The oi'ganisms are imbedded in a fine-grained calcitic 

 rock, which seems to have resulted from the crystallization of 

 a fairly pure calcareous mud. It shows signs of having been 

 indurated by the overlying basalt. 



The foraminifera recognized in the thin slices of this rock are as 

 follows : — 



Cristellaria italica? (Defrance). 



Saracenaria italica, Defrance, 1824, Diet. Sci. Nat., vol. xxxii, p. 177 ; 



vol. xlvii (1827), p. 344, Atlas Conch., pi. xiii, iig. 6. 

 CristcUarla italica (Detr."i, liiadv, 1884, Keport Challenger, vol. ix, p. 544, 



pi. Ixviii, fig's. 17, 18, 20-23. 



A nearly complete lateral and vertical section occurs in this 

 slide {Iso. 2). 



Cristellaria rotiilata'^ (Lamarck). 



Loiticitlitcs rotidata, Lamarck, 1804, Auuales du Museum, vol. v, p. 188, No. 3 ; 



Tahl. Encycl. Meth., pi. 466, fig. 5. 

 Ciisfellaria rotulata (Lamarck), Brady, 1884, Eep. ChalL, vol. ix, p. 547, 



pi. ixix, figs. 13a, b. 



A vertical section, traversing from aperture to the opposite edge 

 in the septal plane. 



Gloligerina hulloides, d'Orbigny. 



G. htUoich's, d'Orbigny, 1826, Ann. Sci. Nat., voL vii, p. 277, No. 1 ; Modele, 

 No. 76 and (young) No. 17 ; Brady, 1884, Eep. Chall., vol. ix, 

 p. 593, pi. ixxvii, and pi. Ixxix, figs. 3-7. 



A specimen somewhat fragmentary, but probably belonging to 

 the above S2)ecies. 



Planorhdina mediterranensis, d'Orbigny. 



r. meditcrranensis, d'Orb., 1826, Ann. Sci. Nat., vol. vii, p. 280, No. 2, pi. xiv, 

 figs. 4-6 ; Modele, No. 79 ; Brady, 18S4, Eep. Chall., vol. ix, 

 p. 656, pi. xcii, figs. 1-3. 



Several specimens, with a more or less neatly rounded contour, 

 like that of the above species, appear in our rock-sections. 



TruncatuUna lohatula ("Walker & Jacob). 



Xautilus lobatuhta. Walker & Jacob, 1798, Adams' Essays, Kanmacher's ed., 



p. 042, pl. xiv, fig. 36. 

 TruncatuUna lobatnla, Brady, 1884, Eep. ChalL, vol. ix, p. 600, pl. xcii, fig. 10; 



pl. xciii, figs. 1, 4, 5 ; pl. 105, figs. 4, 5. 



