. The Annals and magazine of natural history; zoology, botany, and geology. what im-portance to attach to these observations, since no example ofa divided root, so far as I remember, has been figured. It isstated that in the Dryolestidas the canine is inserted by tworoots inore or less distinct. Laodon in this family is men-tioned as having two roots to the canine. In the Diplo- Double-rooted Tooth from the Purheck Beds. 275 cynodontidffi the canine is said to liave two roots, and thecharacter is recognized in the genera Diplocynodon^ Docodon,Euneodon; and in the Spalacotherida? Menacodon is s
. The Annals and magazine of natural history; zoology, botany, and geology. what im-portance to attach to these observations, since no example ofa divided root, so far as I remember, has been figured. It isstated that in the Dryolestidas the canine is inserted by tworoots inore or less distinct. Laodon in this family is men-tioned as having two roots to the canine. In the Diplo- Double-rooted Tooth from the Purheck Beds. 275 cynodontidffi the canine is said to liave two roots, and thecharacter is recognized in the genera Diplocynodon^ Docodon,Euneodon; and in the Spalacotherida? Menacodon is said tohave two roots to the canine. In all these forms no furtherevidence is available from Professor Marshs figures of adivided root, than the appearance of division at the base ofthe crown. Professor Osborn has also affirmed the division of the rootof the canine in an English genus, of which examples arepreserved in the Britisli Museum. First, with regard to thegenus Kurtodon the side of the tooth is stated to show afaint median groove which may indicate a double fang. Miixillary canine of Triconodon ferax. Enlarged 10 times. [root]. Secondly, there is a portion of the jaw of Trico-nodon ferox^ which Professor Osborn describes, and he statesthat it shows as an important character the bifanged upper 276 On a DouhJe-rooted Tooth frum the Purhock, Beds. canine, and it is subsequently added tliat the canine is apowerful tooth implanted by two stout fangs. The toothas iigured (Journ. Acad. Nat. Sci. Philad. 2nd ser. vol. ix. fig. 4) does not bear out the alleged double-rootedcharacter. I have accordingly made an enlarged drawing ofthis tooth, so as to compare with the tooth of Nuthetes. It isexposed on the inner side ; the crown is enamelled at itssummit, with ridges and a slight cinguloid thickening at thebase of the enamel; the extremity of the root of the tooth islost. I have no doubt it is channelled in tlie way ProfessorOsborns figure indicates ; but, from the impressi
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