72 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



vicinity of Mindi Hill ; and 6036 in dark colored, fine grained, sandy 

 clay marl from Monkey Hill, near Mount Hope Station. A figure of 

 one of these is shown in plate 25, figure 3. From 6033<?, Gatun 

 formation, in marl from second bed from bottom, just below lower 

 clay, Gatun section, relocated line of the Panama Railroad, are even 

 more typical specimens, one of which is here figured on plate 25, 

 figure 2. 



Genus SIPHONINA Reuss, 1849. 



SIPHONINA RETICULATA (Czjzek). 



Plate 24, fig. 5. 



Rotalina reticulata Czjzek, Haidinger's Nat. Abb., vol. 2, 1848, p. 145, 



pi. 13, figs. 7-9. 

 Siphonina reticulata Brown, Letbaea Geognostica, ed. 3, vol. 3, 1853-56, 



p. 227, pi. 35 (?), figs. 23a-c— Cushman, Bull. 71, U. S. Nat. Mus., 



pt. 5, 1915, p. 43, fig. 48 ; pi. 16, fig. 4 ; pi. 28, fig. 3. 

 Truncatulina reticulata H. B. Beady. Rep. Voy. Challenger, Zoology, vol. 9, 



1884, p. 669, pi. 96, figs. 5-8. 



Description. — Test biconvex, ventral side slightly more so than 

 the dorsal, peripheral margin acute, carinate; chambers numerous 

 rather indistinct, sutures slightly depressed, curved; wall rather 

 coarsely perforate; aperture peripheral with a short, broad neck and 

 somewhat flaring phialine lip. 



Diameter 0.65 mm. Cat. No. 324679, U.S.N.M. 



The only station at which this species occurred is in the Gatun 

 formation, U.S.G.S. No. 6036, in dark colored, fine grained, sandy 

 clay marl of Monkey Hill, Mount Hope Station. 



Although the specimen is not perfectly preserved the tubuli of the 

 peripheral margin are lacking as is the case in some large recent 

 specimens. 



Family NUMMULITIDAE. 



Genus NONIONINA d'Orbigny, 1826. 



NONIONINA DEPRESSULA (Walker and Jacob). 



Plate 25, figs, oa, b. 



Nautilus depressulus Walker and Jacob, Adam's Essays, Kanmacher's 



ed., 1798, p. 641, pi. 14, fig. 33. 

 Nonionina depressula Parker and Jones, Ann. Mag. Nat. Hist., ser. 3, vol. 4, 



1859, pp. 339, 341.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 



9, 1884, p. 725, pi. 109, figs. 6, 7.— Bagg, Bull. U. S. Geol. Surv., No. 513, 



1912, p. 88, pi. 26, figs. 16fl-c; pi. 28, figs. 7, 8. 



Description. — Test more or less rounded in side view, slighth r 

 elongate, about ten chambers in the last formed coil, apertural view 

 narrow, periphery broadly rounded, sides nearly parallel, about two 

 and a half times as high as broad, umbilicus slightly depressed, 



