Blr, H. J. Carter on the Fossil Foraminifera of Scinde. 377 



belong to their Reticulatce or 2nd group, whereas they have 

 placed it among the Subreticulata or 3rd group, which is distin- 

 guished from the 2nd by the reticulation commencing in simple 

 flexuous lines at the margin first. Nevertheless, from the loca- 

 lities in Scinde from which many of these Nummulites were ob- 

 tained being the same as those from which the specimens of N. 

 sublavigata described by D'Archiac and Haimecame, their inter- 

 nal structure being the same, and from other circumstances which 

 will be stated presently, I cannot consider them as belonging to 

 any other species than N. sublavigata. 



Hence I question whether it would not have been better for 

 these authors to have made only one group of the reticulated 

 Nummulites, and thus to have included all under the head of 

 their second group or Reticulata, instead of adding a tliird, viz. 

 Subreticulatce. The last group seems to me to be superfluous 

 and confusing, especially as the species of Reticulatce, like those 

 of all the other groups, have for the most part so little difference 

 between them that their division is equally perplexing. 



All the specimens that I have, from Scinde and Muscat re- 

 spectively, are in a yellow argillaceous limestone, and those of 

 N. sublavigata, from which D'Archiac and Hairae made their 

 description, were in ''^calcaires marneux, jaunatres, de la chaine 

 d'Hala (Scinde) ;" thus they appear to have come from corre- 

 sponding parts of the same series. Now, this series at Muscat, 

 which is immediately opposite Kurrachee, on the other side of 

 the Gulf of Oman, successively consists, from below upwards, of 

 conglomerate, variegated sands (the yellow colour chiefly pre- 

 vailing), variegated coloui-ed clays (also chiefly yellow), argilla- 

 ceous limestone, ending with pure compact yellowish limestone ; 

 and assuming the Nummulitic series in the neighbourhood of 

 Kurrachee and of the llala Mountains to be the same, it would 

 follow, from the composition and colour of the material in which 

 these Nummulites are imbedded, that they come from the lower 

 part of the series. Hence the Reticulatce, or at least N. sublavi- 

 gata, may be amongst the oldest of the large Nummulites ; 

 unless this part of the series be a middle Tertiarj- one, since 

 D'Archiac and Haime (p. 79) state that the reticulated form 

 named N. garansensis comes from the "first deposits of the 

 middle Tertiaries " in the north-west part of the Pyrenees ; and 

 indeed it has always struck me that the yellow series of Lower 

 Scinde and of Muscat, including that of the island of Masira on 

 the south-east coast of Arabia, which is the same as that of 

 Muscat, was of a later date than the great " white" limestone 

 formation of Upper Scinde, and that of the more elevated por- 

 tions of the south-east coast of Arabia, respectively. Whether 

 or not this is a fact remains to be proved. 



