70 SIR CHARLES ELIOT ON [May 6, 



«;esophagus, whicli is provided with a series of folds, but no liai'd 

 armature of any kind. The stomach is set Avith a belt of horny 

 plates of two sizes and usually alternating legularly, the small 

 lieing next to the large. The pyloric poition of the stomach 

 below this belt is provided with muscular ridges, and passes 

 almost imperceptibly into the intestine. At the point wheie it 

 begins to be constricted is a pouch-like diverticulum Avith a 

 laminated intei'ior. 



With the exception of the absence of jaws, the other chaiacters 

 of thif.' animal cleai'ly connect it with Melibe, not Tethys. The 

 foot is very naiTOW, the body rather high and compressed ; the 

 cerata are covered with knots ; the buccal opening passes straight 

 into the oesophagus ; the stomach is armed with plates ; the liver 

 is long and follicular and does not extend far into the cerata; the 

 hermaphrodite gland is composed of many separate lobes at the 

 side and under the liver. In Tethys, on the contrai-y, the foot is 

 Inoad and the body flat ; the cerata are smooth ; theie is a division 

 of the alimentary canal before the oesophagus which may be called 

 a buccal cavity ; the liver is a compact mass sending diveiticula 

 to the ends of the cerata ; the hermaphi'odite gland forms a thick 

 covering over the liver. Further, Tethys is described as jDOssessing 

 true bianchiae set at the base of the cerata. The back of Melibe 

 fimbriata is coveied with blanched papill;e which bear a superficial 

 lesemblance to gills, but I could not discover that they have any 

 special connection with the vascular system, and they seem ana- 

 logous to the x'amose appendages of Plocamophorus and some 

 species of Notarchus. 



It would thus appear that Melibe fiinhriata is intermediate 

 between Tethys and the jaw-bearing species of Melihe. It does 

 not, however, seem necessary to create a new genus, but rathei- to 

 modify the existing description of the genus and say jaivs jyreseiit 

 or absent. The shape of the foot, body, and cerata, the pi'esence 

 of stomach-plates, the absence of bi'anchi^e, and the character of 

 the liver distinguish it sufficiently from Tethys. 



In spite of its want of jaws, Melibe fimbriata is a most voiacious 

 animal, and I more than once found in the stomachs which I 

 examined limbs of Crustacea moi'e than an inch long. The way 

 in which it captures its prey is extremely cuiious. The circular 

 oral veil acts as a net with an elastic lim. When seeking for 

 food it expands the net and sweeps with it the sru-face over which 

 it is crawling. The skin of the hood is stretched so tight as to be 

 quite transpaient and the marginal cirii are almost invisible. The 

 moment a small crustacean or other prey is caught the net closes 

 up, the cirri almost unite on the under surface, and the skin 

 ceases to be perfectly transparent. Then the Melibe tosses the 

 hood, which has now practically become a closed sac, backwards, 

 and creates a cui-rent of water with the cii'i'i, which forces its 

 prey towards its mouth. The movements of the animal are I'apid 

 and energetic, whether" it crawls or swims. It can also float on 

 the surface foot uppermost. 

 [10] 



