374 Mr. II. J. Carter on the Fossil Foraminifera of Scinde. 



localities mentioned must be referred to N. biaritzensis. They 

 are characterized externally by a single bunch or whorl of septal 

 lines flowing in a sigmoid form from an eccentric point on the 

 disk, towards the circumference (see fig. 5, pi. 8, D'Archiac and 

 Haime), and internally by the regularity of the spire and the 

 chambers, which are much reflected and continue longer across 

 than in the direction of the spire, even to the circumference. 



Here, again, there arc so many varieties, and the species de- 

 scribed by D'Archiac and Haime are so much alike, that it has 

 been exceedingly difficult for me to identify all those which I 

 possess with N. biaritzensis. Nevertheless, after careful com- 

 parison, this has been the conclusion at which I have arrived. 



The number of chambers in one-fourth of a turn half the 

 radius of the fossil from the centre or circumference is only of 

 use where the specimens happen to be of the same size as that 

 from which the typical description is given, since the number 

 of chambers varies in the different turns, and the further the 

 turn is from the centre, the more numerous are the chambers. 

 Thus, if a specimen of N. biaritzensis, 12 millim. in diameter, 

 has eight chambers in one-fourth of a turn half the radius of the 

 fossil from the centre, a specimen of less breadth, which perhaps 

 is the only one possessed, will have fewer chambers in the £ of a 

 turn half the radius from the centre. Hence, as there are many 

 chances to one that the typical size is not possessed, this cha- 

 racter may be of very little service. 



The largest or mean diameter, again, of the specimen requires 

 such an immense number for deduction, that this also is of little 

 use. There appears to me to be no possibility of ascertaining 

 how large any species of Nummulite may be, under a certain 

 limit ; for every day, so to write, seems to bring us a larger one, 

 while the test of full-development to which I have alluded, viz. 

 the approximation of the outer turns of the spire, is only that 

 of the full development or largest size of the locality. 



At one time I thought the striated Nummulites which I pos- 

 sess from Kelat and Sukkur might be referred to either N. bia- 

 ritzensis or N. Viquesneli, while the striated Nummulites from the 

 Booghtee and Murree Hills closely resembled N. Beaumonti. 

 The " posterior superior angle " of the chambers in the Booghtee 

 specimens not being " almost rectangular," and the septa con- 

 sequently being much instead of "little arched," leaves the 

 decision in favour of N. biaritzensis. 



With none of the Nummulites described and figured in D'Ar- 

 chiac and Haime's work have I had such difficulty in identifying 

 my specimens as with the Plicatce vel Striata. 



2. N. Ramondi, Defr., mihi (D'Archiac and Haime, p. 218) 

 (PL XV. fig. 5, &c). — Discoidal, thick; margin angular, wavy ; 



