574 MR. M. F. WOODWARD 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 (protoconid); 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 be :— 
1. Protoconid. 
2. Metaconid. 
3. Paraconid. 
4. Hypoconid. 
This same order of development is presented by the cusps of 
dpm. 4. d 
The probable relation of the dentitions is as follows :— 
(jto2.-3 (a Oe aa: (i) 2 at 
ly an 0 ly Oiere ae e4: d 
Fie 333 a1 PLT Bees 4 3 > M. 
ee Sass (1 {0 2 3 4 (gl ee eek 
ERICULUS SETOSUS. 
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 :— 
fg? Ge a. ie dete aa 
eB O: yee Jo 2 8 4. i 
M38 eve ta we 
CHABAD dad eh eee LO “Dea ald 248 
In a fetal specimen examined, 78 mm. long with a head length 
of 23 mm., a slight differentiation of the dental lamina in the 
lower jaw was observed between i-2 and ¢.,, indicating the last 
trace of 7. 3; but above the reduction is more complete, for although 
there was a conspicuous gap present between i.2 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 lingual side. 
Only a slight lingual development of the dental lamina was 
m. 
m. 1° 
The upper molars, like those of Centetes, are of trituberculate 
form, but possess in addition one slight antero-external cingulum 
observed in connection with 
