( ^97 ) 
v^rfally acquiefced in and they being infufEcient have 
caufed this whole matter, (by the generality of Natura«, 
lifts, even in this Age, ) to be mifunderfliood. ( i .^ Cru- 
Jlaceous Animals^ ( M-olXolh^^q^kol ) fays Ariftotle, are 
foft mthin and hard without, lut whofe covering is not 
apt to he parted hy contufionst tho' one part of it may 
eafily he torn from the other : (So lunderftand his h 
^^vgiv dT^oL i^Act^hv ). ( 2. ) Tejlaceous Animals ('O?*^^» 
uJih^fjxt ) are foft mthin and hard without, whofe co- 
vering may he hruifed or hroken to pieces^ thd its parts 
are not. liahle to he torn from each other ) ^^v<i^v 3i/ it^ 
^cJ^tvlkJov aM' ^ ^Aasrij'. } The Confequences which 
Ariflotie puts into his Definition as Charafteiifticks, 
neceflarily arife from the Doftrine already delivered. 
For when that Sbe/l is but one, as in the whole tejlaceous 
kind^ it may be hruifed, or it may be hroken, according 
as it is more or lefs hrittle, but torn afunder it can ne- 
ver be. Whereas in the whole cruftaceous kind, the co- 
verings which are over every (everal part, as Claws, 
Feet, Back, Belly, and Tail in Lobfters, are joyned each 
to other by MemhraneSy which, tho' tough, may be 
torn afunder, when the particular Crufts, here as well as 
in the tejlaceous kind, cannot. 
According to this Diftinftion 'tis plain, that Echini 
are truly Cruftaceous Animals, for they move upon 
their Spines, which demonftrates that their Covering is 
H h moved 
