468 SYSTEMATIC PALEONTOLOGY 



spire and inferior surfaces. It seems to lack the surface umbilical tuber- 

 cles and is somewhat more compactly built than the larger forms of the 

 type. Only a few forms were dredged by the Challenger expedition 

 from off the Ki Islands at a depth of 500 fathoms. 



Occurrence.-^CuovTA'^K Formation. 1 mile north of Governor 

 Eun, Peach Blossom Creek. 



Collection. — Maryland Geological Snrvey. 



Family GLOBJGERlNlDy^. 



Genus GLOBIGERINA d'Oibigny. 



D'Orbigny in his " Tablean Methodique " describes the genus as fol- 

 lows : " Test free, trochoid, irregular ; spire confused, formed of spheri- 

 cal chambers more or less distinct; aperture in the form of a more or 

 less depressed hollow situated near the axis of the spire in the umbilical 

 angle." 



The shell substance is porous and the shell walls hyaline, and the sev- 

 eral chambers connect watli each other by the opening at the umbilical 

 vestibule. The number of segments varies from three to as many as 

 twenty. The genus is one of the most cosmopolitan known and exists 

 in every latitude, and at every depth, but the forms are all found living 

 at the surface of the sea except G. pacliyderma. It dates from the 

 Jurassic age in the fossil world and became so abundant in the Creta- 

 ceous as to form extensive beds of chalk of great thickness. 



Globigerina bulloides d'Orbigny. 

 Plate C XXXII, Figs. 1, 2. 



Globigerina hulUndes d'Orbigny, 1826, Ann. Sci. Nat., vol. vii, p. '211, No. 1 — Modele 



No. 17 (young) and No. T6. 

 Globigerina bulloides Brady, 1884, CliaL Rept., vol. ix, p. y.)'S, pi. Ixxvii, Ixxix, 



tigs. 3-7. 

 Globigcriua bnlloides Bagg, 1898, Bull. Amer. Pal., No. 10, p. 38. 

 Globigerina bulloides Bagg, I'.IOl, Md. Geol. Survey, Eocene, p. 2.50, pi. Ixiii, figs. 



15, 16, 16a. 



Description. — " Test spiral, subtrochoid ; superior face convex, in- 

 ferior more or less convex but wath deeply sunken umbilicus, periphery 

 rounded, lobulated; adult specimens composed of about seven globose 



