50 GEOLOGY AND PALEONTOLOGY OF THE WEST INDIES. 



species are from U. S. G. S. No. 6854, Rifle Butts, Antigua, and the 

 horizontal section, plate 5, figure 2, from the same station. At this 

 latter station the specimens are very numerous, making up a large 

 proportion of the rock. 



It may be noted here that the material under No. 6854 is of 

 two kinds, as some of the hand specimens are made up almost entirely 

 of Heterostegina and are of a slightly pinkish tinge, while others are 

 white and are made up almost entirely of Lepidocyclina. 



Heterosteginoides antillea, new species. 

 (Plate 5, Figures 5, 6.) 



The following is a description of this species : 



Test small, irregularly lenticular, surface somewhat papillate, in vertical 

 section the central line of chambers slightly irregular, the lateral chambers 

 piled in vertical rows in some specimens, in others variously placed. 



Diameter 2 to 3 mm. or more. 



Type specimens (U. S. N. M. No. 328181) from U. S. G. S. No. 6965, 

 lowest 10 to 15 feet of fossiliferous marls, southwest shore of Crocus 

 Baj 7 , Anguilla. At this station the species is very abundant, making 

 up a large part of the rock. Specimens also are numerous at 6966, same 

 locality, 30 to 50 feet above sea-level, and at 6894, Anguilla. 



This is more regular than its relative, H. panamensis Cushman, from 

 the Canal Zone, although the figured specimen, plate 5, figure 6, is 

 more than usually regular. 



Amphistegina lessonii d'Orbigny. 



(Plate 7, Figure 7.) 



In the Bowden marl there are two distinct forms, possibly species, 

 of Amphistegina. One of these is large, about 3 mm. in diameter, thick, 

 the lower side very granular, the sutures very obscure. The other 

 is about half the diameter, flatter, both sides fairly smooth, a few 

 granules about the aperture, the sutures very distinct. Both these 

 forms are abundant in the Bowden marl of Jamaica. 



Amphistegina lessonii d'Orbigny, variety. 



Specimens of a very thin, biconvex form of this species, with the 

 last-formed whorl making the entire surface of the test, that is com- 

 pletely involute, occur abundantly at Zone A, Rio Gurabo, Santo 

 Domingo. 



Amphistegina lessonii d'Orbigny, e volute variety. 



A large evolute variety of Amphistegina is common at Zone I, Rio 

 Cana, and both Bluffs 2 and 3, Cercado de Mao, Santo Domingo. 



The status of the var'ous species or varieties of Amphistegina is very 

 unsatisfactory. They form a very common constituent of our Tertiary 

 deposits and are often very decided and constant in their characters, 

 especially in fossil material. 



