448 Mr. W. Clark on the Conovulidse, 



foot is transversely divided as in C. bidentatus. The C. albus and 

 erosus of authors are undoubtedly the C. bidentatus. 



This family, with a few of the Bullidce, first show the singular 

 deviation in the position of the eyes from the ordinary gastero- 



pods : I place in it the Otina ?, Velutina otis, which is a 



most curious and anomalous animal, as I cannot find a moi"e ap- 

 propriate provisional depositary for it. I have given a full ac- 

 count of it, that naturalists may form their own opinion of its 

 true position. It inhabits the high littoral levels, from which 

 circumstance, and the structure of the respiratory apparatus not 

 having been made out clearly, it may, if the Conovuli really 

 breathe pure air, have a closer connection with them than ap- 

 pears from their present doubtful position, by having a similar 

 respiration. Though this animal has not the tentacula of Cono- 

 vulus, it has the singular divided foot, and the eyes at the internal 

 points of the head, which is an analogous position to the eyes in 

 Conovulus, and like in it there is no operculum, in which point it 

 also resembles Bulla, as well as in the absence of true tentacula. 

 As far as I can judge at present, this animal appears to be the in- 

 termediate link of the two families ; for assuredly it is not a Bulla ; 

 and though closer to Conovulus than to Bulla, it can scarcely, 

 though closely connected, be deemed its congener. 



Otina ?, Gray. 



Velutina otis, auctorum. 



Animal suboval, auriform, thick, pure white ; the mantle does 

 not extend beyond the shell, its margin is plain ; the head is 

 large, very slightly lobed at its left and right points ; the buccal 

 orifice is a vertical fissure at the under surface, apparently fur- 

 nished with teeth, or a short spinous tongue between the usual 

 buccal mass of a fleshy palate and corneous plates, which are 

 visible through the pellucidity of the head of the animal, with the 

 oesophagus coasting under the light yellow anterior portion of 

 the shell to the stomach. To add to the singularity of this 

 curious creature, the head is so large, that when viewed through 

 the under part of a watch-glass, if the animal is creeping, it has 

 the appearance of a third lobe of the foot, and actually assists in 

 locomotion. The eyes are large, black, placed on rounded pro- 

 minences in the centre of the head : another singular feature is, 

 that not even the rudiments of tentacula exist. The foot is of 

 very unusual structure, being similar to Adanson's ' Pedipes,' and 

 to that of Conovulus bidentatus, the configuration of which was 

 discovered by me many years ago at Exmouth. We refer to the 

 description of the foot of C. bidentatus, which in progression and 

 all other points is, I may say, precisely similar to that of the 



