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E O C 



ries in the several orders of insects, and 

 how far this general transformation and 

 change may extend, without destruction, 

 to its identification. 



ENTOMOSTO'MATA. In the conchological 

 system of De Blainville, the entomosto- 

 mata form the second family of Sipho- 

 branchiata, and include many genera, as 

 the buccinum, dolium, cerithiuna, eburna, 

 and other univalves. 



ENTOMO'STRACA. (from IVTO\HOL, an insect, 

 and offrpaKov, a shell, Gr.) Shelled in- 

 sects. In Cuvier's arrangement the en- 

 tomostraca form the second section of 

 Crustacea. Entomostraca are both den- 

 tated and edentated ; they are mostly mi- 

 croscopic, they are without exception 

 aquatic, and they mostly, though not 

 without exceptions, inhabit fresh water. 

 The entomostracans appear to have been 

 the only representatives of the class Crus- 

 taceans until after the deposition of the 

 carboniferous strata. 



ENTOMO'STRACOUS. Belonging to the fa- 

 mily of Entomostracans. 



ENTOMO'TOMY. (from cvrojua, an insect, 

 and re/ii/w, to cut, Gr.) The dissection 

 of insects, by which we learn their inter- 

 nal construction, and become acquainted 

 with the form and texture of their organs. 



ENTOZO'A. (from IVTOQ and wj), Gr.) 

 Intestinal worms. 



E'NTROCHAL. (from entrochite.) Re- 

 sembling an entrochite ; containing en- 

 trochites. 



E'NTROCHITE. (from iv and Tpo^og, Gr.) 

 Wheel-stone ; a name given to the broken 

 stems of fossil encrinites. Some beds of 

 mountain limestone are almost entirely 

 composed of broken stems and branches 

 of encrinites, frequently called entro- 

 chites. The detached vertebrae of the 

 radiaria are known by the name of tro- 

 chitse ; and when several are united toge- 

 ther, so as to form part of a column, the 

 series is termed an entrochite. The per- 

 forations in the centre of the vertebrae 

 afford a facility for stringing them as 

 beads, from which, in ancient times, they 

 were used as rosaries, and in the northern 

 parts of England they still continue to be 

 known under the name of St. Cuthbert's 

 beads. 



ENVE'LOPE. (envelopper, Fr. invilup- 

 pdre, It.) To enclose on all sides ; to 

 invest with some covering. 



E'NVELOPE. (enveloppe, Fr. involto, It.) 

 A wrapper ; a cover ; an investing inte- 

 gument. 



ENVI'RON. (environner, Fr.) To encom- 

 pass ; to surround ; to enclose on every 

 side ; to encircle. 



E'OCENE. (from ?}w, aurora, and fcaivoc, 

 recens, because, as Mr. Lyell observes, 

 the very small proportion of living spe- 



cies contained in these strata indicates 

 what may be considered the dawn, or 

 first commencement, of the existing state 

 of the animate creation.) M. Deshayes 

 and Mr. Lyell have proposed a fourfold 

 division of the marine formations of the 

 tertiary series, founded on the propor- 

 tions which their fossil shells bear to 

 marine shells of existing species. To 

 these divisions Mr. Lyell has, with the 

 soundest judgment, applied the terms 

 Eocene, Miocene, Older Pliocene, and 

 Newer Pliocene, and well would it be for 

 the advancement of geology, if its nomen- 

 clature were, in all instances, derived 

 from some universal language. In fully 

 explaining the meaning of these terms, I 

 shall borrow largely from Mr. Lyell's 

 Principles of Geology. In proportion as 

 geological investigations have been ex- 

 tended over a larger area, it has become 

 necessary to intercalate new groups of an 

 age intermediate between those first ex- 

 amined; and we have every reason to 

 believe that, as the science advances, new 

 links in the chain will be supplied, and 

 that the passage from one period to 

 another will become less abrupt. All 

 those geological monuments are by Mr. 

 Lyell called tertiary, which are newer 

 than the secondary formations, and which, 

 on the other hand, cannot be proved to 

 have originated since the earth was inha- 

 bited by man. All formations, whether 

 igneous or aqueous, which can be shewn 

 by any proofs to be of a date posterior to 

 the introduction of man will be called 

 recent. The European strata may be 

 referred to four successive periods, each 

 characterised by containing a very dif- 

 ferent proportion of fossil shells of recent 

 species. These four periods will be 

 called, Newer Pliocene, Older Pliocene, 

 Miocene, and Eocene. In the older 

 groups we find an extremely small number 

 of fossils identifiable with species now 

 living ; but as we approach the superior 

 and newer sets, we find the traces of recent 

 testacea in abundance. The latest of the 

 four periods before alluded to, is that 

 which immediately preceded the recent 

 era. To this more modern period may 

 be referred a portion of the strata of 

 Sicily, the district round Naples, and 

 several others. They are characterised 

 by a great preponderance of fossil shells 

 referable to species still living, and may 

 be called the Newer Pliocene strata. 



Out of 226 fossil species brought from 

 beds belonging to this division, M. Des- 

 hayes found that no less than 216 were 

 of species still living, ten only being of 

 extinct or unknown species. Neverthe- 

 less, the antiquity of some Newer Pliocene 

 strata of Sicily, as contrasted with our 



