Mr. H. J. Cai'ter on the Fossil Foraminifera of Scinde, 457 



If, as I have before inferred from its being confined to the 

 lowest deposits of the Nunimulitic Scries, iV. subl^vigata be the 

 oldest form of Nuramulites, then this may be the locality 

 and age of Orhitolites Mantelli; but if, as subsequently stated, 

 this be a ^liddle Tertiary Series, then O. Mantelli and N. sub- 

 lan-igata v\oukl belong to the youngest or latest-formed species of 

 larger Foraminifera, — which I now think most likely, as the bed 

 of Orhitolites Mantelli, Heterostegina, and Cycloclypeus, together 

 with that containing the reticulated Nummulite N. masiraensis, 

 in the island of Masira, on the south-east coast of Arabia, and 

 that containing A", snblcevigata, at Muskat, would then all be in 

 the littoral division of the Nummulitie series of this part of the 

 coast of Arabia, the other or lower division forming the summits 

 of the great scarps a little more inland. 



CoNULiTEs, nov. gen. 



Conulites Cooki, n. sp. (PL XV. fig. 7, &c.). — Conical, dis- 

 coidal, more or less depressed, consisting of a cortical layer of 

 rhomboidal chambers {d) filled with a columnar structure which 

 slightly projects in a convex form beyond the base (c, e). Cor- 

 tical layer composed of a spire of chambers commencing from 

 the apex and terminating at the circumference of the base {d) ; 

 septal lines of the chambers oblique; chambers rounded inter^ 

 nally {1 2, g\). Columnar structure radiated {c,e), consisting of 

 convex layers of compressed chambers, which are more or less 

 arranged in columns, united by stolon-processes, and interspersed 

 with opake white columns (/). Opake columns conical, grow- 

 ing from points on the inner aspects of the chambers and termi- 

 nating in dilated extremities at the base, which thus acquires, 

 when weather-worn, a granular surface {b, e). Apex surrounded 

 externally by a thin columnar growth of shell-substance, which 

 extends about halfway up the side of the cone, and there gra- 

 dually subsides into small granular projections situated on the 

 points of contact between the septa and the spire (ei), 



only a fragment or two of this variety without the centre, to infer that 

 the fossil sometimes had a thalloid growth, like the polypidom of the 

 Polyzoa. 



The Heterostegina is ver}' small, and the Cycloclypeus and OrbicuUna 

 under half an inch in diameter, so far as I have seen ; but probably there 

 are much larger specimens of all these fossils in the deposit. 



In a geological point of view, it is interesting to find Orhitolites Mantelli, 

 Heterostegina, and Cycloclypeus ocairring together in a bed overlying 

 serpentine and diorite rocks in tlie locality above mentioned, since they are 

 found together in a bed in the middle of the south-east coast of Arabia, 

 where the Nummulitie series also reposes conformably on rocks composed 

 of diorite and serpentine. — Bombay, Oct. 12, 1861. 



