42 
TITE GEOLOGIST. 
the Upper Oolitic slates of Cirin, where a lithographic stone some- 
what resembling that of Solenhofen is quarried, there have been dis- 
covered remains of emys-like turtles named Achelonia and Hydro- 
pelta. The Clielone 'planicejys has been obtained from the Portland 
beds, and the curiously complicated and to a certain extent " embry- 
onal" genera Tretosternon and Fleurosternon from the Purbeck. 
In the cretaceous beds we have discovered true marine turtles 
{Chelone Camperi, Chelone Benstedii, and Chelone pulchriceps) ; 
a terrapin {Protemys) has come from the Kentish Eag of Maidstone 
(Lower Greensand), whilst many species of small turtle {Chelone) 
are mingled with the phosphatic nodules of the Cambridge Upper 
Greensand. 
This coracoid bone I recently handed to my friend Mr. Carter 
Eluke for further and more complete examination, and he has kindly 
favoured me with the following note : — 
" This specimen consists of the crushed right coracoid bone, 
viewed from above, of a Chelonian reptile. I have compared it with 
the homologous bone in the varied kinds of Chelonia, and find a form 
which resembles it very nearly in the Matamata {CJielys matamata, 
Gray). The family of turtles to which the matamata belongs is to be 
found in ponds and rivers in warm climates. Dr. Gray tells us that 
they eat flesh, feed only in the water, and when they swim .the whole 
shell is submerged. As however it is believed that the Trigonia- 
bearing Stouesfield slate was a sea-deposit, and as there is no doubt 
whatever that this fossil is really from that bed, there is some degree 
o'f antecedent improbability against its representing a freshwater 
form. Furthermore, taking into account the manifold variations of 
form which the coracoid bone exhibits in the Chelonia, there is really 
no reason, morphological or teleological, why a marine species of 
turtle may not have existed in the Oolitic sea with a coracoid bone 
so far differing in shape from that of the existing marine turtles 
(^Chelone') as to resemble the homologous bone in the matamata. 
The turtle of the Oolite co-existed with the Phascolotlierium and the 
Trigoyiia, much in the same way as the allied genera of turtles, 
CJielymys and Ohelodina, co-exist on the same continent with the 
Australian marsupials, whose remains may be perchance washed into 
the sea where Trigonia still survives. 
" Upon one little fractured bone, however, we must not draw any 
positive conclusions. No doubt, when the Stonesfield slate shall 
have been more thoroughly explored, further evidences will be 
