18 PROCEEDINGS OF THE NATIONAL MUSEUM vol.77 



from the base; sutures depressed, rather distinct; wall smooth; 

 aperture radiate. 



Length 0.33 mm.; breadth 0.12 mm. 



We have one specimen from the Kimmeridge Clay in England 

 which is very similar to Terquem's figures of few chambered specimens. 



Terquem's Figures 16-20 appear to be very similar and may be 

 included in the present species, but as to the others, it is doubtful 

 whether or not they are the same as the present species. 



Distribution. — Terquem reported it from the lower Lias at Beauveau 

 and Auline in France. 



Genus QUADRULINA Cushman and Ozawa, new genus 



Test with the chambers added in planes 90° apart from one another, 

 that is, arranged in a tetraloculine series, at least in the later stage. 

 Genotype .- — Quadrulina rhabdogonioides. 



QUADRULINA RHABDOGONIOIDES (Chapman) 



Plate 1, figures 4 o, 6 



Polymor'phina rhabdogonioides Chapman, Quart. Journ. Geol. Soc, vol. 50, 

 1894, p. 716, pi. 34, figs. 12 a, b. 



"Test subpyramidal and quadrifacial; bluntly pointed at the base 

 and rapidly increasing in width toward the oral extremity. The test 

 is smooth and consists of a Polymorphine series of chambers (slightly 

 twisted as regards the commencement), the margins of which are 

 deeply sunken, and the chambers themselves, numbering about five 

 to seven on each face of the test, well inflated, especially in the case 

 of the more or less central one visible on each face. The terminal 

 chamber is large and embracing, subquadrangular in section, but not 

 regular. The aperture is circular and with margin pectinate. 



"Length one-seventieth inch (0.36 mm.); width diagonally one 

 one hundred and tenth inch (0.23 mm.). 



"The foregoing species is probably a dimorphous form, combining 

 Polymor'phina with Rhabdogonium, and in the event of other varieties 

 becoming known it may be found necessary to form a distinct genus 

 for this type. 



"Two specimens from the pebble beds, Littleton, Bargate Bed of 

 Surrey (lower greensand)." 



We have no specimen of this species. The above is quoted directly 

 from Chapman, and the figures are copied from his plate. 



From Chapman's figures and description the present species seems 

 to have the chambers arranged in a spiral series in the early stages, 

 later becoming tetraserial. 



