30 



BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



One additional feature not noted by the author is the tendency 

 in the larger specimens to have the earliest chambers in a coil. Appar- 

 ently this genus is related, as is Textularia and certain other genera, 

 to an ancestral coiled form, as is indicated by the coiled arrange- 

 ment of the earliest chambers in several genera of the family. This 

 repetition of characters usually occurs only in the microspheric form 

 of the species, which in this case as in many others seems to attain 

 the larger size. 



Genus PAVONINA d'Orbigny, 1826. 



Pavonina d'Orbigny (type, P . flabelliformis d'Orbigny), Ann. Sci. Nat., vol. 7, 

 1826, p. 260.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 374. 



Description. — Test calcareous, hyaline, perforate, many chambered, 

 the early chambers biserial, the later embracing, each embracing por- 

 tion composed of one or more chambers ; apertures numerous at the 

 peripheral margin of the chamber. 



There seems to be but a single well-defined living species, which 

 is rather widely distributed. 



PAVONINA FLABELLIFORMIS d'Orbigny. 



Pavonina flabelliformis d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 260, pi. 10, 



figs. 10, 11; For. Foss. Vienne, 1846, p. 72, pi. 21, figs. 9, 10.— Parker, Jones, 



and H. B. Brady, Ann. 



Mag. Nat. Hist., ser. 3, vol. 



16,1865, p. 27, pi. 1, fig. 22.- 



H. B. Brady, Quart. Journ. 



Micr. Sci., vol. 19, 1879, 



p. 282, pi. 8, figs. 29, 30.— 



Mobius, Beitr. Meeresfauna 



Insel Mauritius, 1880, p. 91, 



pi. 8, figs. 13-15.— H. B. 



Brady, Rep. Voy. Challen- 

 ger, Zoology, vol. 9, 1884, 



p. 374, pi. 45, figs. 17-22.— 



Basset, Ann. Soc. Sci. 



Charente-Inf., 1884 (1885), 



p. 161, fig. in text. — Bagg, 



Proe. XL S. Nat. Mus., vol. 



34, 1908, p. 132. 

 Pavonina flabelloid.es Bronn, 



Klassen und Ordnungen 



Thier-Reichs, vol 1, 1859, 



p. 72, pi. 6, figs. 13a, b — 



Butschli, in Bronn, Klas- 

 sen und Ordnungen Thier- 

 Reichs, vol. 1, 1880, p. 204, 



pi. 18, fig. 13. 



DescrijAion. — Test free, many chambered, much compressed, the 

 early portion consisting of chambers arranged biserially, the later por- 

 tion spreading; chambers in a single series, elongated, forming a fan- 



Fig. 51.- 



Pavonina flabelliformis. a, front view; 

 b, apertural view. X 75. 



