NODOSARIN &. 63 
the Arctic circle to the equator. It occurs in many sandy shore-deposits; but. its 
favorite habitat is mud at 50—100 fathoms, and is continually met with in the 
deepest soundings, although never abundant there, and generally small. 
Dentatina communis, D’ Orbigny. 
Sub-variety—D. paurrrata, D’ Ord. (see above, p. 59). 
Characters.—Shell elongate, sub-cylindrical, composed of many chambers. ‘The 
early chambers sometimes cylindrical, the others more or less ventricose. Shell often 
irregular and unsymmetrical. Length jth to ith inch. 
Dentalina pauperata is a mere name of convenience for certain forms of Dentalina 
communis, in which the chambers have a compact style of growth, the septal lines being 
sometimes quite obscured. Large specimens were not uncommon in the Crag beds at 
Sutton worked by Mr. 8. Wood. 
We find D. pauperata in marls of the Lias, in the Chalk, in the various fossiliferous 
Tertiary clays, and occasionally recent where other Dentaline abound. 
DentaLina communis, D’ Orbigny. 
Sub-variety—D. Brevis, D’ Ord. (see above, p. 59). 
Characters.—Shell stout, sub-cylindrical, consisting of few (three to five) rather 
ventricose and more or less compact chambers. Length ;th inch. 
Of the poorly grown specimens of unstriated Dentaling (or curved Nodosaria radicula), 
the stunted few-chambered forms may be conveniently taken together under D’Orbigny’s 
designation D. brevis. ‘The characters are of little interest or significance, and it is so 
associated in distribution with the sub-typical D. communis as not to require separate 
treatment. Our figured specimen is from the Bridlington Crag. 
Subgenus—V acinuuina, D’ Orbigny. 
OrtHocerAs, Gualtier, Batsch, Hanley. 
Nauti.us, Linné, Martini, Schroeter, Gmelin, Montagu, Turton, Maton and Rackett, 
Dillwyn, W. Wood. 
