Messrs. Hancock and ^mhhton on the Anatomy o/Eolis. 199 



vascular system is at least as perfect in the Eolidida; as in the 

 Dorididae, — 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 MoUusca; 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 Eolididce 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 papillae 

 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 Dorididae, with the exception that in Eolis 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 Eolis, 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 oesophagus, 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 papillae, 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 papillae, ap- 

 parently for the purpose of ensuring its being constantly bathed 

 with aerated 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 luitritive part of the 

 food passes into the blood-current of the system through the 



