84 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Genus BILOCULINA d'Orbigny, 1826. 



BILOCULINA BULLOIDES d'Orbigny. 



Plate 33, fig. 2. 



Biloculina hulloides d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 297, No. 1, 

 pi. 16, figs. 1-4; Modeles, No. 90. — H. B. Beady, Rep. Voy. Challenger, 

 Zoology, vol. 9, 1884, p. 142, pi. 2, figs. 5, 6. 



Description. — Test with but two visible chambers in the adult, in 

 end view, each semicircular, in front view elliptical, very rotund, 

 inflated, suture distinct; aperture usually nearly circular, somewhat 

 produced. 



Length 0.60 mm. Cat. No. 324730, U.S.N.M. 



The only specimen of this species is from the Gatun formation, 

 U.S.G.S. 6036, from dark colored, fine grained, sandy clay marl from 

 Monkey Hill, Mount Hope Station. 



Genus SPIROLQCULINA d'Orbigny, 1826. 



SPIROLOCULINA EXCAVATA d'Orbigny. 



Plate 31, fig. 2. 



Spiroloculina esccavata d'Orbigny, Forarn. Foss. Bass. Tert. Vienne, 1846, 

 p. 271, pi. 16, figs. 19-21.— H. B. Brady, Rep. Voy. Challenger, Zoology, 

 vol. 9, 1884, p. 151, pi. 9, figs. 5, 6. 



Description. — Test planospiral, chambers much elongated, thickest 

 at the basal end, apertural end slightly produced, central portions 

 much excavated, due to the gradual increase in the width of the 

 chambers as added; periphery somewhat convex, angles rounded; 

 sutures distinct except toward the center; apertural end produced, 

 aperture rounded ; tooth wanting in our specimen. 



Length 1.4 mm. Cat. No. 324731, U.S.N.M. 



Specimens were obtained at Station No. 5850, in marl of Pleisto- 

 cene, Mount Hope, Canal Zone, by D. F. MacDonald. 



Genus ORBICULINA Lamarck, 1816. 



ORBICULINA ADUNCA (Fichtel and Moll). 



Plate 33, fig. 3. 



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

 OrMculina adunca Lamarck, Tabl. Encyel. et M6th., 1816, pi. 468, figs. 



2a-c.—H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 209, 



pi. 14, figs. 1-13. 



Description. — Test planospiral, chambers very long, divided into 

 simple chamberlets, sides with alar projections extending nearly to 

 the umbilicus, sutures distinct; apertures numerous, peripheral. 



