THE AMERICAN MUSEUM JOURNAL 



WING OF A FOSSIL Z\Q,^^k — {Lithocicadapeiita C/clL) 

 Direct reproduction from fossil. 



deposited at different times, so that we must assume the presence 

 of intermittent volcanoes somewhere in the neighborhood of the 



lake. The different 

 strata, which have 

 evidently been pro- 

 duced by the as- 

 sorting action of 

 the sluggish lake 

 currents, are often 

 as thin as paper 

 and are not equally 

 fossiliferous. In 

 fact, it is often nec- 

 essary to remove 

 great masses of 

 shale and sandstone before coming on a rich fossiliferous layer, 

 and this, though often traceable for many square feet, may be 

 only a few inches in thickness. The extremely comminuted na- 

 ture of the sediment is responsible for the beautiful preservation 

 of many of the plants and insects, which, in the completeness 

 of their detail, remind one of lithographs or delicate etchings. 



The collections secured by Professor Cockerell and the author 

 show that, although more than 600 species of insects and about 

 150 species of plants 

 have been described 

 from Florissant, the 

 number still to be 

 unearthed must be 

 enormously greater. 

 One may say, in fact , 

 that only the sur- 

 fac9 of the vast de- 

 posits has been 

 scratched. With few 

 exceptions, the Flor- 

 issant insects hith- 

 erto described, though all belonging to extinct species, are never- 

 theless very similar to those found in subtropical America at the 



UNDESCRIBED SPECIES OF FCSSIL BEETLE {MLloid) 

 Direct reproduction from fossil. 



