f *77 ) 
There is in the bottom cf the Right Auricle an ob- 
long Orifice, by which the Blood cometh into its Ca- 
vity from the great Refervoir of the Veins, fituated 
on the back-part of the Heart. This Orifice is furnifhed 
with two Semilunar oblong Valves , difpofed in fuch 
manner, that when the Auricle is relaxed, the Blood 
eftt.rs its Cavity, but when contracted, they (hut 
clofe to hinder the Blood from returning into the Veins : 
The Orifice of the Funnel, or the Conduit into the 
Heart, is to be feen againft the Septum. The Left Auricle 
hath exadtly the fame Structure as the Right : ’Tis in 
the bottom of this Auricle, that the Orifice, common 
to the two Pulmonary Veins, is to be obferved, fur- 
nifhed with two Semilunar Valves $ and againft the 
Septum to the Right, that the Funnel or Conduit into 
the Heart is fituated, joining with the Funnel of the 
Right Auricle. Thefe two Conduits are feparated from 
one another by the continuation of the Septum , which 
divides the Auricles to the very Ventricnle of the Heart, 
and is as a fupport to the middle of the double Valve 
which covers their Orifices in the Heart. 
Of the Vejfels of the Heart. 
I T has been faid before, that from the Bafs of the 
Heart of the Land Tor toife of America, there goes 
out four great Arteries. Of thefe, the firft whieh 
prefents itfelf, (the Torroife being turned upon his Back) 
is the Pulmonary Artery : It is more on the Left Side 
than the others, and is much bigger for the fp2ce of ao 
Inch ^ then ir divides itfeif into two Branches, the mod 
apparent whereof cometh from she Right Side of its 
Trunk, and turns itfelf over towards the Left? Side, ac- 
company^* the Aorta inferior finiftrd, till it hath pierc- 
ed the - encardmm ; after that it unites with the Left 
Branch of the Trachea Arteria y which it accompanies 
through 
