266 EXTINCT MONSTERS. 
one and the same time. We may accordingly take it for granted that 
these imprisoned skeletons were those of foetuses. It is, however, 
very remarkable, that, so far as we are aware, all the skeletons with 
foetuses belong to one single species; thus suggesting that this 
particular species was alone viviparous.” 
It is to be hoped that further discoveries will be made, such as may 
finally settle this question. One would have expected that in some 
cases the young ones, if foctal, would be imperfectly developed. 
