166 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFER A 



periphery quadrate, distinctly lobate, axial periphery rounded ; chambers on dorsal 

 side 15, arranged in 2-| dextrally coiled whorls and increasing moderately in size ; the 

 initial chambers are small, globular, inflated and are followed by subglobular or 

 rather ovoid, large ones ; the last whorl is composed of 4, subglobular and strongly 

 inflated chambers ; on the ventral side the chambers are 4, large, globular, strongly 

 overlapping and moderately inflated ; sutures on the dorsal side slightly curved, 

 strongly depressed ; on the ventral side they are almost straight, radial and strongly 

 incised ; umbilicus extremely small, almost indistinct, slit-like, shallow and open ; 

 aperture interiomarginal, umbilical, in the form of a long narrow arch with a delicate, 

 small lip ; wall calcareous, perforate ; surface finely papillose. 



Dimensions of holotype. 



Maximum diameter = 0-37 mm. 



Minimum diameter = 0-34 mm. 



Thickness = 0-26 mm. 



Main variation. 



1. Chambers 12-16, arranged in 2-|— 3 tightly coiled whorls, and increasing 



moderately in size. 



2. The last whorl is composed of 3^—4 chambers, 4 being most common ; the last 



chamber is usually slightly smaller than the penultimate. 



3. Coiling is random with a tendency to dextral coiling ; (of 77 specimens 



studied, 49 coiled dextrally). 



Remarks. Globigerina haynesi sp. nov. was probably confused with one or more 

 of the following distinct, but morphologically similar species : 

 Globigerina bacuana Khalilov 

 Globigerina spiralis Bolli 

 Globigerina aquiensis Loeblich & Tappan 

 Globigerina chascanona Loeblich & Tappan 



It is distinguished from G. bacuana by its delicately papillose surface, high dorsal 

 side, and raised initial whorls. Globigerina spiralis is distinguished by its smooth 

 surface, greater number of chambers and of whorls, and more tightly coiled test. 

 Globigerina aquiensis which is morphologically very similar to the present species, has 

 a finely hispid surface instead of a delicately papillose one ; G. chascanona is distin- 

 guished by its prominently spinose surface. 



Globigerina hayensi is believed to have evolved from G. spiralis Bolli ; specimens 

 of G. spiralis with a faintly papillose surface are believed to be transitional to G. 

 haynesi, and the stratigraphical ranges of the two species favour this hypothesis. 

 On the other hand, G. haynesi probably evolved into G. velascoensis Cushman by 

 developing a more tightly coiled test, with an angular, depressed spiral suture and a 

 strongly appressed last chamber. 



This species is named after Dr. J. R. Haynes of the Department of Geology, 

 U.C.W., Aberystwyth. 



Holotype. P. 45576. 



Paratypes. P.45577. 



