Mr. H. J, Carter on the Fossil Foraminifera of Scinde. 469 



additional row (1) commences by a stolon from the preceding 

 annular band. From an iminfiltrated specimen. 



N.B. All these figures are more or less magnified, unpropor- 

 tionally. 



Fig. 3. Orbitoiaes asterifera, asteroid variety (?) of 0. dispansa, twice the 

 size of the specimen. 



Fig. A. AlveoUna meandrina,n. sp., nat. size : a, magnified view of surface, 

 showing the tortuous form of the chambers ; b, longitudinal sec- 

 tion through the centre, showing the spiral arrangement of the 

 layers of chambers (the fine lines across the layers represent the 

 vertical canals of the reticulated structure) ; c, transverse section 

 near the centre, showing the spiral manner in which the chambers 

 depart from the longitudinal axis; d, transverse section much 

 more magnified, showing the spiral commencement of the layers; 

 e, magnified view of a portion of the surface, showing, on one 

 side (1) the reticulated plexus of canals which occupies the ex- 

 ternal aspect of the chamber, and corresponds to the " marginal 

 plexus " in the " spicular cord " of Opercidina arabica ; 2, por- 

 tion from which it has been removed, showing the vertical canals 

 between the chambers on which the reticulated portion rested, 

 and thus communicated with the reticulated plexus below (better 

 seen in the next diagram). 



f. Diagram to show the canal-structure surrounding the cham- 

 bers: 1, chambers; 2, marginal plexus or reticulation ; 3, vertical 

 canals uniting the marginal plexuses, and corresponding to the 

 "interseptal canals" in Opercidina. 



Ftg. 5. Orbitolina lenticularis, nat. size : a, conoidal siu^ace ; b, base or 

 patulous surface ; c, lateral view. 



d. Diagram showing — 1, arrangement of chambers at the centre 

 or apex, which is at first more or less confused, and then cyclical; 

 2, external or reticulated chamber-layer; 3, subjacent or large 

 chamber-layer ; 4, engine-turned arrangement of chambers below 

 the last-mentioned layer. 



e. Magnified view of portion of patulous surface, to show the 

 arrangement of the ends of the columnar chambers in the form 

 of granulations. 



/. Horizontal section, showing — 1, reticulated layer; 2, large 

 chamber-layer ; 3, columnar chamber-structure. 



g. Vertical section of half the fossil, showing — 1, reticulated 

 layer externally ; 2, large chamber-layer ; 3, columnar chamber- 

 structure. This section corresponds to fig. / e of Conulites Cooki, 

 but is without the opake white columns of condensed shell-sub- 

 stance, thus bearing the same relation in this respect to Conulites 

 that Orbitolites Mantelli does to Orbitoides dispansa. 



Fig. G. Orbitolina ?, flat variety, nat. size, resembling Cyclolina ere' 



tacea, D'Orb. : a, conoidal surface ; h, concave surface or base ; 

 d, vertical section through the centre. The structure is exactly 

 the same as that of 0. lenticularis. 



Fig. 7. Orbitolina ? (No. 2), nat. size : a, base ; b, diagram showing 



on one side the reticular layer, and on the other the large cham- 

 ber-layer. The reticulated structure is more dense here, and the 

 large chambers larger, than in O. lenticularis. 



Fig. 8. Orbitolina ? (No. 3), nat. size : a, horizontal section ; b, por- 

 tion of surface magnified to show the absence of reticulated 

 structure and imperfectly developed septa of the large chambers. 



