BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 20. AFD. IV. N:0 1. 9 



at that time have been miicli elevated .as is proved by tlie 

 interassociation of mariiie and fluviatile mollusks in the de- 

 posits of the Caloosabatchee». From this it is evident that 

 it coukl not have been then a very favorable time for the 

 forming of a subterranean rivulet. Thns I do not think that 

 vve shall be far wrong, if we snppose the maximum age of the 

 cavern to be postpliocene or still yonnger. The other caves, 

 in which blind Cambari have been discovered, seem to be 

 comparatively niuch older. The Mammoth-cave in Kentucky 

 for instance is excavated in a subcarboniferous limestone for- 

 ming a more or less elevated plateau. The caves in Indiana 

 have a roof of Upper Silurian limestone and are excavated in 

 the Lower. Thus the material in which these are dug out 

 is rauch older and as they are situated on an old continent, 

 which has been upheaved above the sea much earlier than 

 Florida, it is more than probable that they have been formed 

 long before the comparatively small subterranean rivulet in 

 Florida. The size of these other caves indicates also a very 

 much higher age. Thus there is a posmbiUti/ that they have 

 been inhabited by blind forms in a much earlier period and 

 at the same time it is very likely that in them existed blind 

 craytishes long before there were any in Florida. 



But on the other hand it is possible that all animal life 

 in them was extinguished " by the glaciers or by the proximity 

 to them at least in Indiana. The caves all lie however south 

 of the great endmoraine, so it is not (|uite certain. The pre- 

 sence of a species of Cambarus in Alaska shows that they 

 sometimes can stånd a rather rongh climate. I think therefore 

 that it is at least a possibility that Cambarus pellucidus and 

 hamulatus are older than C. acherontis from Florida. The 

 species of Cambarus from the caves of Carnioia ought to be 

 rather old too as the caves themselves are very old and the 

 other species of Cambarus are now all extinct in Europé 

 where there are to be found, with the exception of this one, 

 only representatives of the related genus Astacus. 



Although very little is known about the subterranean 

 watersystem of Florida, I think it must be of a considerable 

 extent. I judge so from the numerous sinkholes I have seen 



' COPE, Packard and other american authors are of the oi)inion that 

 probably the »true subterranean fauna does not date farther back than the 

 beginning of Quaternary or Postpliocene period.» 



