100 



SHOKTER CONTRIBUTIONS TO GENERAL GEOLOGY. 1921. 



Rotalia dentata Parker and Jones. 



riatc XXIII, figure 2. 



Rotalia ihntala Parker and Jones, Philos. Trans., vol. 155, 

 p. ,387, pi. 1!.), fig. IS, l.Sf)5. 



Several specimens from the marl at Byram 

 are very close to this species from Bombay 

 figured by Parker and Jones. They are also 

 close to the figure given by Brady in the Chal- 

 Jeru/iT report (pi. lOS, fig. 4) . /\. dnUata is a dif-, 

 ferent species from R. calcar, though probably 

 included under tliat name by several authors. 



As shown in the figure of the type, the sutures 

 are limbate with clear shell material, and the 

 outer border of each whorl is marked in a like 

 manner. The spinose projections from the 

 edge are very much like those in the figure 

 given by Brady and seem to be different from 

 those ordinarily seen in Ii. calcar. 



Genus ASTERIGERINA D'Orbigny, 1839. 

 Asterigerina subacuta Cushman, n. sp. 



Plate XXIV, figures 1-3. 



Test planoconvex or uneqiuilly biconvex, 

 composed of about three and one-half coils, the 

 dorsal side slightly convex, smooth, the cham- 

 bers all visible in well-preserved specimens, even 

 those of the earlier coils showing through the 

 layer of transparent shell material covering 

 them; chambers about ten in the last-formed 

 coil, the sutures oblique and curved backward 

 but not depressed below the surface, slightly 

 thickened and clear, joining at the periphery 

 witli the slight keel; from below, the chambers 

 of the last coil only visible; sutures ending 

 at a point about one-third of the way in from 

 the jjeriphery, from which a secondary chanilxn- 

 is developed to the umbilical region, where the 

 sutures come together in a central boss of clear 

 shell material; aperture elongate, curved, at 

 the base of the inner margin on the ventral 

 side. Diameter about 1 millimeter. 



Specimens of this species are fairly common 

 in the marl at Byram. It is clearly related to 

 Asterigerina' carinata D'Orbigny and ^4. aiii/u- 

 lata Cushman. From the former it difl'ers in 

 the larger number of chambers and tlie nar- 

 rower coils, and from the latter in the smaller 

 number of the chambers, simpler aperture, 

 and much narrower coils. -4. xuhacuta is 

 nearer A. carinata than ^4. amjulata but is very 

 constant in its characters. From above it has 

 the appearance of a Pulviiuilina, but an ex- 

 amination of the ventral sitle shows the typical 



characters of Asierigerina. It shows traces of 

 granules on the ventral side near the aperture. 



Family NTJMMULITIDAE. 



Genus NONIONINA D'Orbigny, 1826. 



Nonionina umbilicatula (Montagu) Parker, Jones, and 

 H. B. Brady. 



Plate XXIII, figures 3, 4. 



There are several specimens from the marl 

 at Bvram that at present may be referred to 

 this species. It should be noted, however, 

 that the specimens described by Montagu are 

 (Hfferent from many of the forms later as- 

 signed to his species and that there are appar- 

 ently several species or varieties which occur 

 in different regions which should be distin- 

 guished. The specimens from the Byram marl 

 are very constant in all their characters and 

 are very close to one of the forms figured by 

 Brady in the Challenfier report (pi. 109, fig. 8). 

 This species is common in comparatively shal- 

 low water in the Indo-Pacific region, but in the 

 north Atlantic it is found largely in deeper 

 water. It is to be- suspected, therefore, that 

 the species from the Byram marl and that 

 from the Indo-Pacific may be found to be 

 closely allied. 



Nonionina scapha (Fichtel and Moll) Parker and Jones. 



Plate XXIII, figures .5-7. 



A'uiililiis .^muka Fichtel and Moll, Testacoa mieroseopica, 



p. 105, pi. 19, figs, d-f, 1803. 

 Koii:oninn srapha (Fichtel and Moll) Parker and .tones, 



Annals and Mag. Nat. Hist., 3d ser., vol. 5, p. 102, 



No. 1, LSIiO. 

 11. n. Brady, Chalknqer Rept., Zoology, vol. !i, p. 7.30, 



pi. lOQ, figs. 14, 15^ 1(1?, 188-1. 



There are two forms of Nonionina in the 

 Byram marl, both of which are referred to N. 

 scapha. One of them is very close to two of 

 the figures given by Brady in the Challenger 

 report (pi. 109, figs. 14, I.")). The other is 

 somewhat more elongate. Both forms are 

 figured here to facilitate subsecjuent reference 

 when the various forms of Nonionina found in 

 the Tertiary of the Coastal Plain may be 

 studied as a whole. 



Genus NTJMMULITES Lamarck, 1801. 

 Nummulites sp. 



Plate XXIV, figure 1. 



There are a few specimens of Nummulites 

 from the marl at Byram of the character 



