232 JO URN A L, BOMB A Y NA TURAL EISTOR Y S0C1E TY, Vol. XX. 



vided with a cutting instrument to incise the egg-shell and release themselves 

 from their ovicular imprisonment. As far as I am aware this is an observation 

 new to science. 



One might have supposed that a very moderate pressure from the snout 

 of a vigorous embryo would suffice to rupture membranes which appear so 

 delicate, but this is evidently not the case. 



I was able after some trouble arising from the minute proportions of this 

 structure — which when removed is only just visible as a speck to the naked 

 eye — to view it under the microscope, and it will be seen from the accom- 

 panying figures that in conformation it is very different from the analogous 

 organ of an oviparous embryo, some remarks upon which and a figure were 

 published in this Journal some time back *. 



cL 



A B C 



Foetal tooth of I»achesis jerdoni. 



(much enlarged). 



A. Inferior surface. 



B. Superior surface : — 



(a) root ; (b) inferior surface ; (c) flattened superior 

 surface of bill ; (d) cutting anterior edge. 



C. Seen in profile. 



D E 



D. Pr^emaxilla of foetus of Lachesis jerdoni seen from front, showing 

 arch (e) beneath which the bill (d in fig. B) projects. 



E. Pr/emaxilla seen from below showing the socket (/) into which the 

 root of the foetal tooth (a in fig. B) fits. (#) shows anterior surface. 



* Vol. XVIII, p, 504. 



