AMERICAN SPECIES OF ORTH OPHEAGMIN A AND LEPIDOCYCLINA. 



43 



Orthophragmina sculpturata Cushman. 



Plate VIII, figiires 3-7. 

 Orthophragmina sculpturata Cushman, Carnegie Inst. 

 Washington Pub. 291, p. 54, pi. 9, figs. 8, 9, 1919. 



Test circular, somewhat sellaeform, in many 

 specimens very slightly so; central portion 

 considerably thickened and occupying one- 

 third to one-quarter the diameter of the test; 

 peripheral portion much flattened and com- 

 paratively thin; exterior of central thickened 

 portion, when well preserved, beautifully 

 sculptured, with comparatively few raised 

 papillae, between which the surface is depressed 

 and reticulated as in 0. marthae Schlumberger ; 

 peripheral thin portion of the test usually 

 smooth when the surface is well preserved. 



Vertical sections show thickening up to 

 1.5 millimeters in the central portion, while 

 the periphery may be but 0.25 millimeter in 

 thickness. Equatorial chambers small, in- 

 creasing hardly at all in diameter from the 

 center to the periphery; central embryonic 

 chambers not well shown in the sections but 

 at least six to eight times the diameter of 

 adjacent equatorial chambers. Peripheral por- 

 tion without pillars; central portion with very 

 strong pillars, thick, with a diameter of one- 

 third to one-half their length and increasing 

 very slightly in diameter toward the surface; 

 lateral chambers in columns between the pillars, 

 very thin compared to their breadth. Central 

 portion of the outline decidedly undulate from 

 the projecting ends of the pillars. 



Horizontal sections show very numerous 

 equatorial chambers, elongate, several times 

 as long as broad; lateral chambers in section 

 appearing as polygonal lighter spaces sm-roxmd- 

 ing in a single row the solid, opaque, circular 

 elliptical, or irregularly polygonal pillar sections ; 

 toward the periphery, where the pillars are 

 wanting, forming an irregular network — the 

 same arrangement as in 0. dispansa Sowerby.^ 



Diameter, 5 to 7 millimeters. 



Type specimen 3478, from Nuevitas, Cuba; 

 A. C. Spencer, collector. Sections were also ob- 

 tained in material from the Cadiz mine, Oriente 

 Province, Cuba; E. F. Burchard, collector. 



This species in general appearance resembles 

 0. martTme Schlumberger, especially in its char- 

 acteristic surface ornamentation, but the verti- 

 cal section seems to be verydi fferent from that 

 figured by Schlvunberger. 



1 Schlumberger, Soc. g^ol. France Bull., sec. 4, vol. 3, pi. 12, fig. 51, 1904. 



Orthophragmina hayesi Cushman, n. sp. 



Plate VIII, figures 8-10. 



Test small, lenticular, circular, compara- 

 tively thick in the center, thence gradually 

 becoming thinner and at the peripheral portion 

 in the adult extending out into a broad, thin 

 flange; central disk with numerous deep pits, 

 circular or polygonal, usually four or five in 

 the central region of larger size, the surround- 

 ing ones gradually smaller as they are more 

 distant from the center ; remainder of the surface 

 reticulate, from the lateral chambers as they 

 come to the exterior. 



Equatorial chambers of the usual rectan- 

 gular form of this genus. 



Vertical sections (PI. VIII, fig. 10) show the 

 large number of lateral chambers in each 

 column and the flangelike peripheral portion 

 not shown in the exterior views of the worn 

 specimens (figs. 8, 9). 



Tyi^e specimens (U. S. N. M. No. 32820) 

 from U. S. G. S. station 6411, Brito forma- 

 tion, coast about 2 miles northwest of Brito 

 Harbor, Nicaragua; C. W. Hayes, collector. 



Orthophragmina marginata Cushman. 



Plate IX, figures 1, 2. 



Orthophragmina marginata Cushman, Carnegie Inst. 

 Washington Pub. 291, p. 56, pi. 1, fig. 2; pi. 2, fig. 4, 

 1919. 



Test circular, lenticular; central portion 

 strongly raised and umbonate; regularly curved 

 down to the broad peripheral flange, which 

 is agaui thickened near the peripheral margin; 

 surface comparatively smooth, very slightly 

 granular but not at all papillate. 



In vertical section the central portion is seen 

 to be strongly biconvex, not much wider than 

 either part of the surroimding margin-like thin- 

 ner portion, again thickening toward the ex-, 

 treme peripheral margin, which is rounded. 

 Equatorial chambers small, in the center very 

 narrow but increasing slightly although grad- 

 ually toward the periphery, where they are not 

 more than 0.1 millimeter in height. The 

 chambers are convex on the peripheral side, 

 almost semicircular in some specimens. Lat- 

 eral chambers very small and often difficult to 

 distinguish even with an enlargement of 20 di- 

 ameters (PI. IX, fig. 2). In the central portion 

 there are large numbers of layers of the lateral 

 chambers, often 30 to 40 on either side of the 

 equatorial band. This number decreases as the 



