128 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



Globotruncana rosetta rosetta (Carsey) 

 (PL 8, figs. 3a-d) 



1926 Globigerina rosetta Carsey : 44, pi. 5, figs. $a-c. 



1931 Globotruncana area (non Cushman) ; Plummer (pars) : 195, pi. 13, figs, ga-c, na-c 

 (non figs, ja-c, 8a-c). 

 ? 1937a Globotruncana rosetta (Carsey) Glaessner : 39, pi. 1, figs, \-za-c. 

 ? 195 1 Globotruncana rosetta (Carsey) : Bandy : 509, pi. 75, figs. ^a—c. 

 ? 1951 Globotruncana cretacea Cushman ; Tilev (pars) 62-67, text-figs. ioa-d, non 2ia-d 



(see also Tilev 1952 where figures are repeated). 

 ? 1954 Globotruncana rosetta (Carsey) ; Nakkady & Osman : 84, pi. 19, figs. -ja-c. 

 ? 1955 Globotruncana rosetta rosetta (Carsey) ; Gandolfi : 66-67, pi- 6, figs. la-c, text-figs. loa-c. 

 ? 1955 Globotruncana bollii Gandolfi : 62-63, pi. 5, figs. la-c. 



1956 Globotruncana rosetta (Carsey) : Bronnimann & Brown : 545-546, pi. 21, figs. 11-13. 



1962 Globotruncana rosetta (Carsey) : Barr : 575, pi. 70, figs. ^a-c. 



Description. Test large, planoconvex, coiled in a very low trochospire ; dorsal 

 side almost flat, ventral side distinctly protruding ; equatorial periphery subcircular, 

 moderately lobate, with two very closely spaced keels on the early part of the last 

 whorl reduced to a single keel on the later chambers ; axial periphery angular with 

 the ventral side almost at right angles to the flat periphery ; chambers on the dorsal 

 side 18, arranged in 3 dextrally coiled whorls ; the initial chambers are small, inflated, 

 globigerine, increasing slowly in size, and followed by typically crescentic, flattened 

 chambers which increase moderately in size ; the last whorl is composed of 6, 

 relatively large, typically crescentic, flattened chambers which increase slowly in 

 size ; on the ventral side the chambers are 6, relatively large, angular conical, 

 strongly inflated, slightly overlapping, distinctly protruding and increase so slowly 

 that they appear to be all roughly equal in size ; sutures on the dorsal side curved, 

 slightly raised and delicately beaded with the beading fading out gradually towards 

 the last chamber ; on the ventral side the sutures are radial and slightly depressed ; 

 umbilicus roughly stellate in outline, relatively wide, deep, bordered by delicately 

 beaded ridges and covered by complex tegilla of which remnants are preserved ; 

 primary apertures interiomarginal, umbilical ; tegilla, with accessory apertures, only 

 poorly preserved ; wall calcareous, perforate, except for the imperforate keels, 

 peripheral band and tegilla ; surface delicately papillose especially on the ventral 

 side and in the early part becoming smoother towards the last chamber. 



Dimensions of described specimen. 

 Maximum diameter = 0-52 mm. 

 Minimum diameter = 0-47 mm. 



Maximum thickness = 0-30 mm. 



Variation. The main variation observed is in the degree of flattening of the 

 dorsal side, protrusion of the ventral side, and surface rugosity. 



Remarks. Globotruncana rosetta rosetta was first described by Carsey (1926) as 

 Globigerina rosetta n.sp. White (1928) transferred this species to the genus Globo- 

 truncana although his figured specimen probably belongs to the G. stuarti group. 

 Plummer (1931) considered the present species to belong to G. area (Cushman) 



