DIEECTIONS TOE COLLECTING FOSSILS. 471 



with regard to their individual position, whether shells for 

 instance, are found all exhibiting the same view ; or if fishes 

 affect a general uniform position or parallelism of their sides 

 to the stratification ; and such other peculiarities as cannot 

 generally be exemplified even by whole suites of specimens. 



9. Uncommonly interesting are the osseous remains of 

 caverns and grottos which frequently occur in limestone 

 rocks ; these should be diligently sought after and visited, 

 oven where report may represent them as not being 

 ossiferous. The collector, in his examination, should proceed 

 systematically by cutting through the layers of the incrusta- 

 tions which he may find at the bottom of them, and which 

 are formed by the dripping down of water impregnated with 

 calcareous particles ; let him form a series of specimens from 

 the layers of this stalagmitic deposit ; as likewise of the 

 alluvial matter beneath it, of the gravel, sand, and mud, 

 which usually envelop the osseous remains. Of these latter 

 he should form a complete series, not only as regards the 

 natural difference he may observe in the several bones, but 

 likewise the accidental changes observable in them, such as 

 appearances of being gnawed, fractured, &c. Also other 

 objects which may be found near to, or accompanying the 

 bones, such as rounded concretions, fragments o*f stones 

 different from the rock of the cave should be collected, and 

 their manner of occurring noted on the labels. In the same 

 manner the collector should not neglect recording every 

 circumstance which the specimens alone are not calculated 

 to illustrate, such as the distribution of the various bones in 

 the caverns, their relative abundance, &c. He should also 

 make memoranda relative to the nature and situation of the 

 cavern itself, its direction, its dimensions, the presence or 

 absence of water in it ; or whether it be furnished with 

 fissures, particularly vertical ones ; and if so, whether these 

 be partly open, or filled with bones and rubble cemented 

 together ; whether parts of the sides near the opening 

 exhibit a polish as if produced by rubbing against ; together 

 with other appearances which are likely to strike an atten- 

 tive observer. 



If fissures in limestone rocks should, on examination, prove 

 to be filled with osseous remains, cemented together by 

 calcareous and other matter, it will be desirable, for the 



