46 BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



Genus ARCHAIAS Montfort, 1808 



Archaias Montfort, Conch. Syst., vol. 1, 1808, p. 191. — Cushman, Special 



Publ. No. 1. Cushman Lab. Foram. Res., 1928, p. 220. 

 Helenis Montfort, Conch. Syst., vol. 1, 1808, p. 195 (genoholotype, 



Helenis spatosus MonUoTt = Nautilus aduncus Fichtel and Moll). 

 Holes Montfort, Conch. Syst., vol. 1, 1808, p. 199 (genoholotype, Ilotes 



rotalitatus Montfovi = Nautilus orbiculus Fichtel and Moll). 

 Orbiculina Lamarck, Ency. Method., pt. 23, 1816, p. 468 (genotype, by 



designation, Nautilus aduncus Fichtel and Moll). 



Genoholotype. — Archaias spirans yLontfort = Nautilus angulatus 

 Fichtel and Moll. 



Test in the early stages planispiral and lenticular, bilaterally sym- 

 metrical, in later stages becoming flaring, even annular; wall imperfo- 

 rate except in the very earliest chambers which are perforate, divided 

 into chamberlets; apertures in several rows on the apertural face. 



Miocene to Recent. 



ARCHAIAS ANGULATUS (Fichtel and Moll) 



Plate 16, figures 1-3; plate 17, figures 3-5 



Nautilus angulatus Fichtel and Moll, Test. Micr., 1803, p. 112, pi. 21. 

 Archaias angulatus Cushman, Special Publ. No. 1, Cushman Lab. Foram. 



Res., 1928, p. 218, pi. 31, fig. 9. 

 Orbiculina angulata Lamarck, Anim. sans Vert., vol. 7, 1822, p. 609, No. 2. 

 Archaias spirans Montfort Conch. Syst., vol. 1, 1808, p. 190, 48* genre. 

 Nautilus aduncus Fichtel and Moll, Test Micr., 1803, p. 115, pi. 23. 

 Orbiculina adunca Lamarck, Tabl. Encycl. M4th., 1816, pi. 468, figs. 2o-c. — 



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



nif^res", p. 81, pi. 8, figs. 8-14 (and later authors). 

 Nautilus orbicularis Fichtel and Moll, Test. Micr., 1803, p. 112, pi. 21. 

 Helenis spatosus Montfort, Conch. Syst., vol. 1, 1808, p. 195, 49* genre. 



( = Nautilus aduncus Fichtel and Moll). 

 Ilotes rotalitatus Montfort, Conch. Syst., vol. 1, 1808, p. 199, 50* genre. 



{ = Nautilus orbiculus Fichtel and MoU). 

 Orbiculina numismalis Lamarck, Hist. Anim. sans Vert., vol. 7, 1822, 



p. 609.— Defrancb, Diet. Sci. Nat., vol. 32, 1824, p. 180; vol. 36, 1825, 



p. 291; Atlas Conch., pi. 15, fig. 4 (and later authors). 



Test much compressed, the early portion close coiled, later becoming 

 more or less complanate or even circular, periphery truncate; early 

 chambers simple, later ones divided into a series of chamberlets by 

 partitions generally at right angles to the periphery, distinct, elongate, 

 low; sutures distinct, depressed; wall imperforate, milky-white, with 

 numerous shallow punctations of the surface but not forming perfora- 

 tions, in the earliest chambers, the proloculum and immediately 

 following chamber, perforate; aperture in the early stages, as in 

 Peneroplis, a narrow sUt, then a series of pores, one to each chamberlet, 

 in a slight depression in the median line of the peripheral face. 



Miocene to Recent. 



This species is very abundant in the West Indian region, and very 

 much less so in the Indo-Pacific. In the western tropical Atlantic, 

 it is often the dominant species in comparatively shallow water. 



