48 THE PALEONTOLOGY OF MINNESOTA. 



[Nonionina 



pores on the face of the terminal segment. The septa are double, and the skeleton 

 is furnished with a system of canals the general features of which are analogous to 

 that of Nummulites." 



Locality. Meeker county, Minnesota. Specimens of this variety have been identified in the Eocene 

 at Jackson, Mississippi. 



Sub-Family 2. POLYSTOMELLIKE. 



NONIONINA, d'Orbigny. 

 NONIONINA SCAPHA Fichtel and Moll. Sp. 



PLATE E, FIGS. 35, 36. 



Nautilus scapha FICHTKL and MOLL, 1803. Test. Micr., p. 105, pi. xix, flgs. d-1'. 



Nonionina sloani d'ORBiGNY, 1839. Foram. Cuba, p. 68, pi. vi, fig. 18. 



Nonionina scapha PARKER and JONES, 1860. Ann. and Mag. Nat. Hist., ser. 3, vol. v, p. 102, No. 4. 



Nonionina boneana REUSS, 1863. Bull. Acad. Roy. Belg., ser. 2. vol. xv, p. 156, pi. iii, flgs. 47, 48. 



Nonionina scapha BRADY, 1865. Nat. Hist. Trans., Northd. and Durham, vol. i, p. 106, pi. xii, flgs. 



10, a, b. 

 Polystomella crispa var. (Nonionina) scapha PARKER and JONES, 1865. Phil. Trans., vol. civ, p. 404, pi. 



xiv, flgs. 37, 38 ; pi. xvii, flgs. 55, 56. 

 Nonionina scapha BRADY, 1884. Report on Foram., H. M. S. Challenger, Zool., vol. ix, p. 730, pi. cix, 



flgs. 14, 15 and 16 ? 



".Testa spiralis involuta subovalis, utrinque umbilico impresso parvo, lateribus 

 mediocriter convexis (minus quam in prsecedente Non. faba, sed magis quam in 

 sequente N. crepidula) ; dorso obtuso ; articulis duodecim conspicuis, subelevatis, 

 laevibus ; dissepimentis antrorsum meaiocriter convexis, non omnibus ex centro 

 radiantibus, sed tribus ultimis parum extra vagantibus ; piano orali oblongo sub- 

 cordato convexo ; orificio (in specimine obvio unico partim detrito) praesumtive, uti 

 in aliis similibus, lineari parabolice arcuato." 



Shell spiral, involute, suboval, slightly umbilicate on both sides, sides moderately 

 convex (less than in the preceding N. faba, but more than in the following N. crepi- 

 dula), back obtuse ; with twelve conspicuous chambers ; subelevate, smooth ; par- 

 titions moderately convex anteriorly, not all radiating from the centre, the last three 

 a little eccentric ; the plane of aperture oblong, subcordate, convex ; aperture (in 

 specimen figured somewhat worn away) probably as in similar species, linear para- 

 bolic arcuate. 



The following description will make the above more comprehensible. 



"The test of Nontonina scapha is of elongate oval contour, and more or less 

 compressed, the peculiar form being due to the rapid increase in size of the later 

 segments. This increase is not merely in the length of the chambers, but also yi 

 their thickness. The peripheral edge of the later portion of the test is obtuse or 

 rounded, and the exposed septal face of the final segment varies from oval to more 

 or less cordate."^ BRADY, loc. cit. 



locality. South Chicago, Illinois. 



