1 860.] JONES AND PARKER FORAMINIFERA. 299 



We may suppose the Amphistegina-bed of Pienza to have been 

 formed at no great depth ; perhaps at not more than 10 fathoms, if 

 we are swayed by the presence of the R. Beccarii and P. crispa, as 

 indeed we ought to be. 



Amphistegince form a large proportion of the material of some 

 other fossil deposits in the neighbourhood of the Mediterranean (as 

 shown in columns Nos. 17, 18, 20, 21, & 23). It abounds in the 

 white Nussdorf marl of the Vienna Basin ; and is not absent from 

 the Malaga clay. It may yet be found in some part of the Mediter- 

 ranean ; but, as it seems to have disappeared from this area, geologists 

 may be right in setting a value on its abundance in some of the 

 Tertiary beds, and in regarding it as indicative of the Miocene 

 period. It abounds in the Miocene Tertiaries of San Domingo. 



No. 16. Clay from Monti Arioso (Meneghini). 

 The fauna here is made up of Botalia Beccarii with a few other 

 shallow-water forms. 



No. 17. " Sabbie giallc," Montopoli (Strozzi). 



This yellow sand much resembles in its fauna No. 15 ; but the 

 Ampliistegina is here accompanied with a larger suite of Rotalice, 

 Puli/stoynelhe, Textidarice, &c, with some Miliolce. The varieties 

 here present indicate rather deeper water than that peculiar to the 

 fauna of No. 15. 



No. 18. Caste! Arquato (Strozzi). 



This also has Ampliistegina. It contains also Operculum com- 

 planata, which is, however, feebly developed in the Mediterranean ; 

 but this is very rare at Caste! Arquato, and may have been a 

 " derived " fossil, being very much worn. This deposit was formed 

 in shallow water, and has much agreement with the fauna of column 

 No. 1, in its many well-developed littoral forms. 



No. 19. " Delle Crete Scnesi" (Strozzi). 



This, like No. 14, is extremely rich in llotalia Beccarii. It has 

 also many good-sized specimens of Polystorru Ua crispa, a few Miliola . 

 and a unique specimen of Dactylo/wra, which Looks worn, like a 

 " derived " foBfliL Dactyl <>]><>r<t is a characteristic Hocene Forami- 

 nifer; it is not found in the Mediterranean; hut the subtropical 

 seas yield some small specimens, exhibiting, as it were, an arrest of 

 growth*. It occurs also in the Miocene clays of San Domingo. 



No. 20. San Frediano (Strozzi). 



Another Amphistegina-bed with a low littoral forms besides its 

 abnndanl Amphistegince. Polystomella is again Large and common, 

 as in most of the Amphistegina-deposits. 



No. 21. Tejares Clay, Malaga (Anated). 



What we have said respecting column No. L2 holds good for the 

 Rhizopodal fauna afforded by this Malaga clay. At from 17" to 500 

 fathoms in the Mediterranean rarj man] of the same group of forms 

 occur, but the individuals arc smaller. At from L100 to 1700 fathoms 

 there are fewer, and man] of them \in small; but Orbulina and 

 * Bee AjinaU of Nat But Srdaer. rol. v. y- 173. 



