54 SHALLOW-WA lEK FORAMINIFERA OF TORTUGAS REGION. 



the coral blocks and dead shells were thickly spotted with the tests 

 belonging to this species. In the most perfectly formed of these 

 specimens the test is made up of a circular mass about 8 mm. in 

 diameter, slightly raised above the surface, and with numerous aper- 

 tures, one central and the others arranged in a ring above this, near 

 the periphery. The details of the surface are very similar to those 

 figured by Hickson. Where these specimens are protected from 

 wear, being in cavities, the apertures are even more elongate, and 

 living specimens have a crown of spicules about each of these, as 

 shown (plate 14, fig. 8). The plates near the edge are more coarsely 

 perforated than those of the main body of the test. The spicular 

 crowns are made up of entire or broken sponge-spicules, pieced 

 together in a peculiar manner. Some of these are shown (text- 

 figs. 4, 5). One of these in more detail is given (text-fig. 6) and a 

 portion of this is enlarged to show the method of cementing. These 

 have a transparent cementing material which seems to be more or 

 less elastic. It is difficult to determine the precise character of the 

 material; strong acids apparently had no effect in dissolving it. 

 With these are certain pinkish forms, apparently distinct from the 

 deep red of the Homotrema, and which are very rare, compared 

 with the deep-red form. These need careful study and comparison 

 with similar forms from other parts of the West Indies. 



Genus ASTERIGERINA d'Orbigny, 1839. 



Asterigerina carinata d'Orbigny. 



(Plate 9, Figures 4 to 6.) 



Aaterigerina carinata d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 1839, "Forami- 

 nifferes," p. 118, pi. 5, fig. 25; pi. 6, figs. 1, 2. — Cushman, Carnegie Inst. Wash., 

 Pub. 291, 1919, p. 45; Proc. U. S. Nat. Mus., vol. 59, 1921, p. 60, pi. 14, figs. 6 to 8. 



Test unequally biconvex, coiled, the dorsal side very slightly convex, the 

 ventral side strongly so, almost conical; chambers numerous, about 3 coils, 

 6 or 7 forming the last-formed coil; sutures oblique, very slightly limbate, 

 produced to form a slight translucent keel ; sutures curved and oblique on the 

 dorsal side, on the ventral side the supplementary chambers extending nearly, 

 to the periphery, forming rhomboid areas; sutures distinct, very slightly 

 depressed; wall smooth, finely punctate and usually glistening, often some- 

 what roughened by lines of small granules near the aperture, which is an 

 elongate, narrow slit, extending from the umbilical region about halfway to 

 the periphery, and usually with a slight, thin lip. 



Diameter of the Tortugas specimens not usually exceeding 0.6 mm. 



This is described by d'Orbigny from the shore sands of Cuba and 

 Jamaica and I have recorded it from Jamaica and from the Miocene 

 of Santo Domingo, from Bluff 2, Cercado de Mao, and it extends as 

 far north as Cape Hatteras and probably is widely distributed in 

 the West Indian region. Brady did not place the species of Asteri- 

 gerina as synonyms in the Challenger report, but mentions them as 

 "probably related to Amphistegina." They do have somewhat the 



