98 BULLETIiSr 104, UNITED STATES NATIONAL MUSEUM. 



In the material examined there are megalospheric specimens which 

 occur with typical microspheric ones but which do not show as 

 clearly the early conical condition. This is in conformity with so 

 many genera that show the full characters only in the microspheric 

 form and which in the megalospheric form do not show these as well, 



The extension of range of this genus from its earliest discovery is 

 noted under the distribution of the type species. 



AMMODISCOIDES TURBINATUS Cushman. 



Plate 36, figs. 3-6; plate 37. 



Avimodiscoides turbinatus Cushman, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 424, 

 pi. 33, figs. 1-6. — Rhumbler, Foram. Plankton-Exped., pt. 2, 1913, p. 388, 

 text figs. 124a, d. 



Description. — Test in the microspheric form with a proloculum 

 followed by a long, coiled, nonseptate chamber, in the young form- 

 ing a hollow cone of about 10 coils. The whorls of nearly uniform 

 diameter, later portion broadl}^ flaring, concave, whorls increasing 

 in diameter toward the periphery, peripheral edge somewhat flat- 

 tened; wall of fine sand grains with a chitinous cement, surface 

 smooth, of a dark reddish brown color; aperture low and broad, 

 quadrangular, without a definite lip. 



Maximum diameter of microspheric specimens, 3 mm. 



Distribution. — The tj^pe station for this species is Albatross D2383. 

 in the northern portion of the Gulf of Mexico, in 1,181 fathoms. 

 The specimens from this station w^ere found in material selected by 

 Goes mider the name Ammodiscus incertus. In a reexamination 

 of the unsorted material from this station other specimens were 

 found. Also it has been found in material from six other stations 

 in the same general region; D2377, 210 fathoms, bottom, tempera- 

 ture 67° F.; D2384, 940 fathoms, bottom temperature 39.6° F.; 

 D2385, 730 fathoms, bottom, temperature 40.1° F.: D2393, 525 

 fathoms, bottom temperature 41.1° F.; D2398, 227 fathoms, bottom 

 temperature 48.6° F.; and D2399, 196 fathoms, bottom temperature 

 51.6° F. Widely separated from this general area specimens occurred 

 at D2760, in 1,019 fathoms, bottom temperature 39.5° F., off the 

 eastern coast of South America, near Bahia, Brazil.* 



The species seems to be limited to this distribution and southern 

 in its tendencies. It has not been found in any of the abundant 

 material off the eastern coast of North America from Florida to 

 Newfoundland nor in the other portions of the Gulf of Mexico or 

 the Caribbean Sea from which material has been examined. 



It is also worthy of note that the species does not seem to occur 

 usually with Ammodiscus incertus. 



