two new Species o/" Hectocotyle. l.'i 



It may, however, be conjectured that the intestine, if it does not end in a 

 caecum, 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. J^ascular 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 branchiae, 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 ^ths of a line in length and 

 ^th 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 branchiae 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 brancli, 

 which, after having formed some ramifications, is connected by capillary 

 anastomosis with the branchial veins. The branchial arteries take their origin 

 from two venae cavae, 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 



