> as lemmas

1893 W. B. Scott in Proc. Acad. Nat. Sci. Philadelphia 1892 412 As early as the Puerco, however, we find that p⁴ in every known genus is complicated by the addition of a second cusp upon the inner or lingual side of the protocone, which may be called the deuterocone.

1922 W. K. Gregory Origin & Evol. Human Dentition ii. i. 104 A similarly situated, but better developed, basal cingulum in later mammals may be traced from the premolars, where it gives rise to the so-called ‘deuterocone’ or internal spur, backward to the ‘protocone’ of the molars.

1968 R. Zangerl tr. B. Peyer Compar. Odontol. 188 W. B. Scott thus proposed a special terminology for the description of the premolars, in which the cusps are simply numbered as protocone, deuterocone, tritocone, tetracone, and ‘-conid’ respectively.