two new Species of Hectocotyle. 13 
It may, however, be conjectured that the intestine, if it does not end in a 
czecum, passes into the part which I have called penis, and ends at its ex- 
tremity. With regard to minute structure, the intestine is composed of an 
exterior muscular layer and a thick epithelium. 
d. Vascular System. 
Though I have not been able to investigate the whole vascular system 
clearly, yet I have seen enough to convince me that it is more complex than 
could be expected from the simple external form of the animal. 
_ The heart is situated in the middle of the back between the branchize, on the 
outside of the above-mentioned muscular envelope of the body, being covered 
only by the skin. It has an oval shape, being about ;*5ths of a line in length and 
sth of a line in breadth, and seems to consist of an auricle and a ventricle. As 
I only discovered the heart after my return from Italy, in dissecting the indivi- 
duals brought with me in spirit, I can say nothing about its contractions; nor 
am I able even to explain its connexion with the vessels. The only fact which 
I distinctly saw is, that two large vessels take their origin from the heart, the 
one from the part which I judge to be the auricle, the other from the ven- 
tricle. 
With regard to the vessels of the branchize and the body my inquiries have 
been more successful. On each side of the back of the animal there are in 
the cephalic portion, just beneath the branchial appendages, two large vessels 
close together: the one situated most externally, which has a diameter of 
0:096", may be called the branchial artery ; the other, of 0:048" diameter, the 
branchial vein. 
The branchial arteries give to each ‘branchial appendage a single branch, 
which, after having formed some ramifications, is connected by capillary 
anastomosis with the branchial veins. The branchial arteries take their origin 
from two venz cave, which come from the posterior part of the body, and are 
formed by the junction of all the smaller veins of the body, among the most 
conspicuous of which are those of the generative organs and the skin. 
The branchial veins are formed by a great number of small veins, which 
take their origin from the above-mentioned system of capillaries included in 
the branchial appendages. I could not trace these vessels to the heart ; neither 
