618 PROFESSOR E. RAY LANKESTER. 
strongly marked divisions of the King Crab’s heart, being 
originally placed in corresponding segments of the body. At the 
BHM 
4 
cK 
a 
a 
He HHH @ a 
A 
Fie. 18.—Heart and origin of the supra-spinal artery. 4, of the Scor- 
pion (Buthus), after Newport; B, of Limulus, after Milne-Edwards. 
Ito VI, arteries to the six pediform limbs; VII to XIV, the eight 
chambers of the heart; sp, supra-spinal artery ; ce, cerebral arteries ; 
c, caudal artery ; /, lateral anastomatic artery of Limulus. 
anterior margin of each division there is a pair of valvular 
apertures, and there are accordingly eight pairs in each 
heart. At the hinder margin of each division in the Scor- 
pion a pair of lateral arteries is given off (eight pairs in all) ; 
such lateral arteries exist only in connection with the first 
three divisions of the King Crab’s heart, their place being 
taken by secondary longitudinal trunks (woodcut, fig. 19, 2). 
From the base of the truncus arteriosus, that is, just in front 
