TEXTULARIIDAE — TEXTULARIA; BIGENERINA; BOLIVINA. 25 



Genus BIGENERINA d'Orbigny, 1826. 

 Bigenerina nodosaria d'Orbigny. 



(Plate 2, Figures 5, 6.) 



Bigenerina nodosaria d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 261, pi. 11, figs. 9-11; 

 Modules, 1826, No. 57. 



Test composed of two portions, the early textularian biserial portion, 

 much compressed, generally triangular in front view, followed by a uniserial 

 series, the wall arenaceous, usually of calcareous grains, rather neatly 

 ^cemented; aperture in the early portion like that of Textularia, in the uniserial 

 portion becoming central, terminal, generally circular; color grayish- white. 



Length of the Tortugas specimens up to 1.5 mm. 



There seem to be two distinct forms in this species, developed in 

 the Tortugas collection. The first is like that figured by d'Orbigny 

 and others, in which the early textularian portion is broad, making 

 up in length about one-half of the entire test, followed by 3 or more 

 chambers, circular in cross-section, but w^hose diameter is con- 

 siderably less than that of the early portion; the second form (which 

 is common in this collection from the Tortugas) has a biserial 

 portion, very small, and which may be followed by 6 or more cham- 

 bers in a uniserial arrangement, increasing in size as added and 

 becoming considerably greater in diameter than the early biserial 

 portion. It may be that these represent the first megalospheric and 

 the second microspheric form of a single species, both forms usually 

 occurring together and the specimens being clearly one or the other 

 tehout intermediate forms. This species is one of the commonest 

 in the collection, and it seems strange that d'Orbigny had nothing 

 in his Cuban monograph which can be definitely referred to this 

 species. 



Genus BOLIVINA d'Orbigny, 1839. 

 Bolivina pulchella (d'Orbigny). 

 (Plate 1, Figures 8, 9.) 



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



niferes," p. 150, pi. 1, figs. 23, 24. 

 Bolivina costata Goes (not d'Orbigny), Svensk. Vet. Akad. Handl., vol. 19, no. 4, 1882, 



p. 71, pi. 4, figs. 129 to 132. 

 Bolivina caribcea Goes (not d'Orbigny), Bull. Mua. Comp. Zool., vol. 29, 1896, p. 48. 



Test rhomboid in front view, gradually increasing in width from the 

 subacute base, the last-formed two chambers making the maximum width; 

 chambers numerous, distinct; sutures slightly depressed, obUque, the outer 

 angle of each chamber ending in a spinose point; wall ornamented by long- 

 itudinal costse, each ending at the peripheral angle of the chamber in a shght 

 projecting spine; wall thin and translucent; aperture elongate, extending 

 from the base of the inner margin of the chamber to the distal point of the 

 last-formed chamber, usually with a shght elevated hp. 



Length up to 0.4 mm. 



From a study of the Tortugas specimens it seems probable that 

 they are the same as that described by d'Orbigny as Sagrina pul- 

 chella. In the front view in the original figures the margin of each 



