Mr. H. J. Carter on the Fossil Foraminifera of Scinde. 461 



resemblance between the two so close, that I hardly think that 

 it should be considered otherwise than as a variety of the latter. 

 It scarcely differs more (that is, in the specimens in my posses- 

 sion) than in being a little smaller than the Heterostegina of 

 Malta. 



The resemblance of the horizontal face of this fossil to Orbi- 

 toides dispansa sen Prattii while in the matrix, led me to think 

 that it was that Foraminifer — an error in both editions of my 

 Memoir on the Geology of the south-east coast of Arabia (loc. 

 cit.) which I thus take the opportunity of correcting. As before 

 stated, I did not meet with Orbitoides dispansa in Arabia, nor 

 have I ever found Orbitoides dispansa together with Orbitolites 

 Mantelli; and as I have also before stated, it was the mistaking 

 of the small specimens of this Heterostegina among those of Or- 

 bitolites Mantelli for Orbitoides dispansa which led to my giving 

 a section of Heterostegina as illustrative of the ' ' multispiral " 

 commencement of the chambers in the latter. 



Cycloclypeus, Carp. 



Cgcloclypeus mammillatus, n. sp. — Circular, thin, presenting a 

 prominence in the centre surmounted by a large tubercle, which 

 is again surrounded by a number of minute ones, the latter 

 passing off in broken lines to terminate in a radiating spiral 

 manner upon the margin. Margin thin, not inflated. Cham- 

 bers circular in the centre, becoming oblong and quadrangular 

 towards the circumference, arranged in rows, witli their long 

 axis in the direction of the horizontal or long radius of the fossil. 



Largest size. — I could only obtain one specimen entire, which 

 was —^ inch in diameter. 



Loc. Takah, on the south-cast coast of Arabia, in white lime- 

 stone, with Orbitolites Mantelli and Heterostegina. 



Obs. — Here the minute granulations, instead of being on the 

 lines separating the rows, are over the septal divisions between 

 the chambers themselves. Thinking, from my limited means of 

 examination, and from its being associated with Heterostegina, 

 that this fossil must be considered one of the same genus, 1 gave 

 it the above specific designation ; but having lately cut away a 

 little of its surface, to examine its internal structure, I find that 

 it is distinctly a Cycloclypeus. 



The cells of this specimen diminish in size towards the centre 

 and become almost globular; but this may be because the cen- 

 tral cell happened to be minute instead of large. In Dr. Car- 

 penter's typical form, however, the cells are deeper in the centre 

 and become shallower outwards ; and if this be always the case, 

 then C. mammillatus follows what I have considered to be the 

 normal form of the horizontal planes in Orbitoides dispansa and 



