80 SHALLOW-WATER FORAMINIFERA OF TORTUGAS REGION. 



Peneroplis cylindraceus (Lamarck). 



PenerofAis cylindracrus H. H. Brady, Rep. Voy. Challenger, Zoolojo". vol. 9. 1884. p. 205, 

 pi. 1.1, figs. 20, 21.— Cushman. Proc. U. S. Nat. Mu3., vol. .j9, 1Q21. p. 75. pi. IS. 

 fig. 11. 



Single specimens occurred at but two stations. These were in 

 very fine sand and in comparatively quiet water. As this is a very 

 delicate species, it may be that its occurrence is much more frequent 

 than these records would indicate. In the Jamaican material a 

 single specimen only was obtained. 



Peneroplis discoideus Flint. 



Peneroplis pertuaua (Forskal) var. discoideus Flint. Rep. U. S. Nat. Mus., 1897 (1899), 

 p. 304, pi. 49. figs. 1, 2.— Cushman, Carnegie Inst. Wash.. Pub. 291. 1919. p. 69. 



Peneroplis discoideus Cushman, Proc. U. S. Nat. Mus., vol. 59, 1921, p. 76, pi. 18, fig. 20; 

 pi. 19. figs. 1 to 3. 



Very fine specimens of this species, which the late Dr. Flint de- 

 scribed from Key West Harbor, occurred in the Tortugas region. 

 It is widely distributed in the West Indies and is apparently found 

 as far back in the fossil series as the Miocene. 



Subgenus MONALYSIDIUM Chapman, 1899. 



Chapman places in this subgenus specimens evidently allied to 

 Peneroplis, but the surface ornamentation, consisting of rows of 

 minute tubercles, the early chambers spiral, the later development 

 linear. Such specimens have occurred in the Tortugas collection as 

 single specimens, only at a few stations. They are so delicately 

 brittle that it seems probable that they were broken before they 

 were studied. Heron- Allen and Earland question whether or not 

 such forms as are figured here have any spiral early portion. Speci- 

 mens which 'they had from the Kerimba Archipelago, east coast of 

 Africa, apparently have an aperture at either end of the straight 

 test. In the specimens figured by Brady (Challenger report, plate 

 13, figs. 24, 25) the chambers are separated by a collar-like portion 

 and one end only shows traces of the aperture. Our specimens 

 from the Tortugas are very similar to those figured by Brady, except 

 in the form of the chambers themselves. These usually are broader 

 at the basal end than at the apertural end. In all our specimens one 

 end has a distinct aperture with a definite, projecting lip, the other 

 end in no case shows such a condition. From the shape of the 

 chambers alone it would usually seem possible to orient the specimens. 



Monalysidium polita Chapman? 

 (Plate 13, Figure 4.) 



Peneroplis lituus H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884. p. 205, pi. 13, 



figs. 24, 25 (?). 

 Peneroplis (Monalysidium) polita Chapman, Journ. Linn. Soc. London, Zoology, vol. 28, 



1902, p. 4, pi. 1, fig. 5 (?). 

 Monalysidium polita Heron-Allen and Earland, Trans. Zool. Soc. London, vol. 20, 1915, 



p. 603, text-fig. 43 G. 



