(PART 2 of 2) +----------------+-------------+ | | Number of | | | Species | | NAMES OF +------+------+ |CLASSES, ORDERS,|In the|In the| | OR FAMILIES. |living|fossil| | |state.|state.| | | | | | | | | +----------------+------+------+ |Polyparia, | 527 | 414 | |Stellaridæ, | 76 | 4 | |Echinidæ, | 95 | 112 | |Annulosa, | 17 | 29 | |Serpulacea, | 36 | 69 | |Cirripeda, | 50 | 17 | |Tubicolæ, | 11 | 16 | |Pholadaria, | 12 | 4 | |Bivalve shells, | 1009 | 1104 | |Univalve shells,| 1945 | 1544 | |Genera little | | 5 | | known, | | | |Crustacea, | | 54 | |Pisces, | | 183 | |Mammifera & | | 89 | | Cetacea, | | | |Aves, | | 3 | |Reptilia, | | 23 | |Insecta, | | | |Vegetabilia, | | | +----------------+------+------+ (a) The fossil remains of birds being very difficult to be recognized, the number of genera in that state is undoubtably much more considerable. THE END. FOOTNOTES: [1] See Note A, at the end of this Essay. [2] See Note B. [3] The opinion maintained by some geologists, that certain strata have been formed in the inclined position in which they are now found, admitting it true with regard to some particular strata which might have been crystallized, as Mr Greenough supposes, like the deposit which encrusts the inside of vessels, in which water containing gypsum has been boiled, cannot at least apply to those which contain shells or rolled stones, which could not have waited, so suspended, the formation of the cement by which they were to be agglutinated. [4] See Note C. [5] The conjecture of the Marquis de la Place, that the materials of which the globe is composed, have perhaps existed at first in the elastic form, and have successively assumed a liquid consistence on cooling, and have at length been solidified, is well supported by the recent experiments of M. Mitscherlich, who has composed, of all sorts of substances, and crystallized by the heat of intense furnaces, several of the mineral species which enter into the composition of primitive mountains.--Note D.