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



Fig. 9. Orbitolina ? (No. 4), nat. size: a, diagram showing long 



chambers of surface in upper part, and vertical section through 

 the centre, below. 

 Fig. 10. Operculina arabica : spicule magnified, showing shreds of the 



interspicular substance (a) attached to it. 

 Fig. 11. The same. Truncated end of the "spicular cord," the arrange- 

 ment of the great horizontal canals of the " marginal plexus," 

 and the spicules in alternate layers more or less radiating from a 

 central point : a, spicular cord ; b, spiral laminae ; c, cavity of 

 chamber ; d, truncated ends of canals ; e, truncated ends of spi- 

 cules ; f, vertical tubuli of spiral laminae ; g, projection of a por-. 

 tion of the spicular cord into the chamber. 



Here it will be observed that all the truncated ends of the 

 spicules are not of the same size, which arises from their being 

 so arranged as to interdigitate and overlap each other longitudi- 

 nally in the general structure, the point of one ending over the 

 middle of another, &c. The projecting portion into the chamber 

 (g) only happens where the cord is prolonged inwards to receive 

 the " interseptal canals." 



[This diagram, in its prominent features, is drawn from nature, 

 with the minor and unimportant detail supplied from imagination 

 and memory.] 



Fig. 12. The same. Portion of the outer part of a chamber (taken from a 

 dried specimen in which the animal was living when it was taken) 

 relieved from its calcareous matter by a very weak solution of 

 nitric acid and alcohol : a, lateral portion of chamber made up of 

 small bodies having a hole or depression in the centre, being the 

 remains of the vertical tubuli; b, "bodies" more magnified; 

 c, septal boundary of chamber in which these bodies are absent, 

 but presenting canals of communication between the cavity of 

 the chamber and the interseptal canals, all now rendered mem- 

 branous ; d, interseptal vessel ; e, chamber laid open, showing 

 small and large reproductive spherules in its cavity, and passing 

 through the canals of intercommunication (fff) into the inter- 

 septal canal. 



Fig. 13. The same. Small reproductive spherule, composed of a globe 

 of glairy substance surrounded by a transparent spherical capsule. 

 1 -5400th of an inch. 



Fig. 14. The same. Large reproductive spherule similarly composed, but 

 with the central portion become opake and granular. Size 

 l-1800thofaninch. 



Compare these two figures with the propagative spherules of 

 Amoeba verrucosa, Ehr., and Euglypha pleurostoma, Cart. (figs. 12 

 & 19, pi. 1. vol. xx. Ann. Nat. Hist. 1857) and of E. alveolata 

 (figs. 32 & 33. pi. 5. vol. xviii.). 



Fig. 15. Nummulites Ramondi, mihi; vertical section of some of the outer 

 chambers highly magnified to show the presence of the propaga- 

 tive spherules and the two great "spiral canals" of Dr. Carpenter: 

 a, spicular cord ; b, spiral laminae ; c, chambers ; d, continuation 

 of the chamber towards the centre; e, spherules; f f, truncated 

 ends of the great spiral canals ; g, interseptal canal sending off 

 two branches to communicate with the great spiral canals re- 

 spectively. 



