34 ME. A. L. ADAMS ON THE OSTEOLOGY OF 



is almost ground down to the top of the penultimate ridge with the rudimentary and 

 digitated posterior talon at its base. Here fourteen ridges are held in space of 7" 2 inches ; 

 there is much parallelism of the disks, and a comparative thinness of plates ; and their 

 enamel is quite in keeping with the last. Possibly these may be only sexual differences. 

 In all the above teeth the discal pattern is alike, showing very faint crimping of the 

 machserides in well-worn crowns, with the central expansion and angulation. Less perfect 

 molars of the same dimensions are represented by Nos. 57 and 40 of the Collection. 



The nearly perfect upper molar No. 93 (PI. VIII. figs. 1 & 1 a) contains fifteen ridges 

 in 7 '5 inches. It differs from the foregoing only in the presence of an extra ridge. 

 The posterior talon here is only a diminished ridge rising from the common base with 

 the others. 



A fragment. No. 68 of the Collection, is referable to the same type. 



A mutilated lower molar, No. 36, with several of its ridges depressed from an 

 injury when the tooth was fresh, is no doubt on this account considerably lengthened, 

 from the infiltration of matrix at the seat of fracture. The last ridge here is of the 

 same character as in PL VIII. fig. 2, with the same flattening internally at its base. 

 The cement has been I'emoved by accident from the tops of the last three collines, which 

 alone are unworn ; therefore the tooth is far advanced and under all circumstances 

 should have maintained indelible marks of pressure on its last ridge, which is not the 

 case. 



Probably No. 36 did not exceed materially the dimensions of any of the foregoing, to 

 which it assimilates in all particulars ; only the enamel is, if any thing, thicker. The 

 worn disk shows the faint crimping and pronounced central angulations. 



T) Series (thick-plated). — The members of this series are unfortunately very imperfect ; 

 but what remain transcend in dimensions any of the foregoing. 



1. A fragment. No. 78, shows six and a half of the posterior ridges of an upper 

 molar in a space of 4'3 inches ; so that if the tooth held fourteen ridges, like the pre- 

 ceding, it must have been fully 9 inches in length. It is remarkable for the massive 

 appearance of the plates ; and although the crown is considerably abraded, its disks are 

 well shown. The three anterior pretty well indicate the original dimensions of the 

 plate; the first, being the broadest, was no doubt one of the central ridges. It is 2-5 

 inches in breadth, and 0'5 inch in thickness, which would equal the same in the second 

 true molar of Elephas antiquus. The last three ridges display large circular digitations 

 in pairs, which are from 0-5 to 1 inch in breadth. The parallelism of the plates is 

 of course pronounced, seeing that the section is close to the base. There is distinct 

 faint crimping of machserides and abrupt angular expansions ; the latter, however, are 

 not very conspicuous, but quite as much so as obtains in the members of C Series. 



2. The fragment of a lower molar. No. 55 (PI. VIII. fig. 7), was unfortunately all 

 that could be saved of an entire tooth after having been knocked about by the workmen. 

 It was found close to the last, and, indeed, may have been the opposing tooth of the same 



