612 PROFESSOR E, RAY LANKESTER. 
may mention that Dufour (‘ Mémoires de 1’Institut Sciences 
Math. et Phys.,’ vol. xiv, 1856,) has given an account 
which is based upon the examination of freshly killed speci- 
ments of Scorpio occitanus. In regard to the alimentary 
canal and its appendages, Dufour is probably correct where 
he differs from Newport, the divergence being due to the fact 
that Newport studied the large oriental species of Buthus, 
whilst Dufour made use of the species above-named. Differ- 
ences in the account given by Dufour of the nervous and 
circulatory systems are not thus to be explained, and with- 
out definitely concluding that Dufour is entirely wrong in 
his statements, I have felt justified in accepting Newport’s 
account as accurate. Newport, unfortunately,did not complete 
his figures of the alimentary system nor give any proper 
account of them. Hence Dufour’s contribution to this part 
of the subject is of increased value. 
In both Scorpio and Limulus the alimentary canal consists 
of an axial tube which takes a median course without lateral 
convolution from mouth to anus. It presents a suctorial or 
ingestive portion in front, and a widened “ proctodzeum,” or 
hind-gut posteriorly. The mouth in Limulus is not placed 
so far forward as in Scorpio, but has a considerable area of 
the cephalothorax in front of it. Resulting from this posi- 
tion we find that the suctorial or pharyngeal portion of 
the tract is bent sharply upon itself, passing from the mouth 
forwards to the front of the head, and then turning upwards 
and backwards to pursue a median course to the anus. This 
bent pharynx of Limulus is a powerful suctorial organ, and 
is lined within by chitinous ridges. The food of Limulus 
consists of soft-bodied worms, which are sucked into this 
organ and crushed by it. 
Corresponding to the bent pharynx of Limulus is the 
pharyngeal sac of Scorpio, the mechanism of which was 
described by Professor Huxley in this Journal (1860). The 
Scorpion’s pharynx is adapted to the sucking up of the juices 
of other animals which it kills, but never draws within the 
boundaries of its exceedingly minute oral aperture. 
Following upon the pharynx of Limulus, and separated 
from it internally by a valvular arrangement, is the digestive 
portion of the alimentary tract. It is remarkable for pre- 
senting two pairs of tubular outgrowths, which are the stalks 
of the huge saffron-coloured gland which fills up the space 
offered by the horseshoe-shaped carapace, and even extends 
into the region of the abdomen. The digestive section of 
the alimentary tract runs through the whole series of appen- 
dage-bearing segments, and in the telsonic region joins the 
