574 MB. m;f. wooDWAED ON [May 5, 



it ; indications of the paraconid and metaconid are just visible as 

 antero- and postero- internal shoulders to the main outwardly 

 inclined cone (protocouid) ; of two former cones the metaconid 

 appears to develop a trifle the earliest, as in m. 2 the paraconid is 

 not yet visible ; in neither teeth had the hypoconid yet made its 

 appearance. The order of development is thus shown to bo : — 



1 . Protoconid. 



2. Metaconid. 



3. Paraconid. 



4. Hypoconid. 



This same order of development is presented by the cusps of 

 dpui. 4. 



The probable relation of the dentition's is as follows : — 



(123 fl C0 234 fl234 



.1 



^■< 1 2 3- ^"i I' ^"i 2 3 



(^123 1^1 (_0 234 1^1234 



EBI0ULT7S SETOSOS. 



The dentition of this genus is somewhat specialized, inasmuch as 

 there is a distinct reduction in number of teeth, the 3rd incisor 

 above and below being, in addition to the 1st premolar, completely 

 wanting. In the case of the functional teeth possessed by 

 Ericulus, the replacement is complete and may be represented as 

 follows : — 



fl 2 fl fO 2 3 4 fl 2 3 



tJi 2 p J 1. p J o 2 3 4 J J 



1^1 2 \l [0234 1^1 2 3 



In a foetal specimen examined, 78 mm. long with a head length 

 of 23 mm., » slight difierentiation of the dental lamina in the 

 lower jaw was observed between r2 and ci, indicating the last 

 trace of iTS ; but above the reduction is more complete, for although 

 there was a conspicuous gap present between i-^ and ^, yet all 

 trace of the dental lamina was lost. 



The canines develop close to the 2nd premolar, and no indication 

 of the missing 1st premolar was to be found. 



Examination of the 4th premolar shows that ppm. 4 develops 

 conspicuously in front of dpm. 4, the former being distinctly 

 between dpm. 3 and dpm. 4, but on their Ungual side. 



Only a slight lingual development of the dental lamina was 



observed in connection with -^. 



The upper molars, like those of Centetes, are of trituberculate 

 form, but possess in addition one slight antero-eiternal cingulum 



