NO. 4 PLANKTONIC FORAMINIFERA — CIFELLI 23 



LL. The percentages dropped in the fall, when the maximum was 

 only 9 percent (station 9, in the Sargasso Sea) but increased in the 

 winter, when the maximum was 17 percent (Sargasso Sea station 

 MM). 



Genus HASTIGERINA Thompson, 1876 

 HASTIGERINA PELAGICA (d'Orbigny) 



Plate 7, figures 1, 2 



Nonionina pelagica d'Orbigny, 1838, Foram. Anier. Merid., p. 27, pi. 3, figs. 



13, 14. 

 Hastigerina murrayi Thompson, 1876, Bolli, Loebuch, and Tappax, 1957, 



U. S. Nat. Mus. Bull. 215, p. 29, pi. 3, figs. l-3b. 

 Hastigerina pelagica Bradshaw, 1959, Contr. Cushman Found. Foram. Res., 



vol. 10, pt. 2, p. 47, pi. 8, figs. 14, 15.— Be, 1959, Micropaleontol., vol. 5, 



No. 1, pi. 2, figs. 21-22. — Banner and Blow, 1960, Micropaleontol., vol. 6, 



p. 20, text fig. 1. 



The test consists of a highly involute, biumbihcate planispiral coil 

 of inflated chambers that is sometimes compressed laterally. A 

 trochoid stage was not observed. The aperture is an equatorial open- 

 ing at the base of the last chamber that varies in size from a slit to a 

 broad arch. Above the aperture is a thin lip. The wall of the test is 

 very thin and extremely fragile, and specimens are often in a poor 

 state of preservation, even from plankton tows. The spines are few 

 in number but are coarse and triradiate (Banner and Blow, 1960, 

 p. 21). The spines extend into, and even through, the walls of the 

 chambers from the previous whorl. 



Hastigerina pelagica is one of the most distinctive and easily 

 recognizable Recent planktonic species. It is most readily comparable 

 with GlobigerineUa aeqtiilaterlaUs, but I agree with Parker (1962, p. 

 228) in retaining these two species in separate genera. As Parker 

 states, a much better case can be made for combining H. pelagica with 

 Hastigerinella digitata, as these two latter species are unique in their 

 spinosity. 



Distribution. — This species reached a maximum frequency of 24 

 percent in the summer at Sargasso Sea station (LL) but otherwise 

 occurred mostly in low percentages. The winter maximum was 13 

 percent (Sargasso Sea station KK), but the fall maximum was only 

 3 percent and the spring maximum only 1 percent. 



Genus GLOBIGERINOIDES Cushman, 1927 



The genus Glohigerinoides includes a distinctive group of species 

 with peculiar chamber arrangements that tend to deviate considerably 



