Messrs. Hancock and Embleton on the Anatomy of Holis. 199 
vascular system is at least as perfect in the Holidide as in the 
Doridide,—nay even as complete as in the majority of the Gas- 
teropoda. 
- Secondly, the nervous system has been shown to consist of 
ganglia well-developed and concentrated, and of numerous and 
large nerves ; the eye, the ear, taste perhaps, certainly common 
sensibility exist, smell as well, and if our views be correct, to as 
high a degree as in any of the Mollusca; in short, the nervous 
system has reached a grade of organization higher than in the 
majority of the Gasteropods. This is most important evidence 
that the Holidide are not in the degraded state implied by Phle- 
benterism. 
_ Thirdly, in these animals the respiratory system may be looked 
upon as somewhat less specialized than in other Gasteropoda, but 
it is sufficiently developed and specialized in the branchial papille 
to prevent us from attributing its function, even in part, to the 
prolongations of the digestive system. 
Fourthly, we have pointed out the singular development and 
complexity of the genital organs, which are not in these respects 
inferior to many other Gasteropoda, and certainly similar to the 
genitalia of the Doridide, with the exception that in Hols the 
ovarium is much more bulky. 
_ Fifthly, from the certainly not lower state of development of 
those systems of organs we have enumerated, it ought not to be 
expected that there should be any degradation of the digestive 
system of Kolis, and accordingly we find fleshy sensitive lips with 
_superadded tentacles, a strong muscular buccal mass with horny 
cutting jaws, and a spiny prehensile tongue, minute salivary ap- 
paratus, a constricted cesophagus, a well-marked stomachal sac, 
with the adjunct of a distinct intestine ending in a lateral anal 
nipple. So far we find no deviation from the Gasteropodous 
type; the liver however is as it were broken up into as many 
pieces as there are branchial papille, and which by a series of 
ducts of variable number communicate with the stomach. Why, 
it may be asked, does the hepatic organ not occupy its usual 
place in the body ? The enormous development of the ovary we 
suppose necessitates the removal to the exterior which we observe, 
and the organ thus thrust out is divided among the papille, ap- 
parently for the purpose of ensuring its being constantly bathed 
with aérated blood, whilst at the same time by this arrangement 
the body of Eolis is kept of small dimensions, a condition pro- 
bably rendered necessary by some peculiarities in the ceconomy 
and habits of the creature with which we are unacquainted. By 
this arrangement also the hepatic artery becomes unnecessary., 
Phlebenterism supposes that the chyle or nutritive part of the 
food passes into the blood-current of the system through the 
