OTINA. 295 



O. OTIS, Turton. 



O. otis, Brit. Moll. iii. p. 321, pi. 99. f. 2, 3 ; (animal) pi. O. O. f. 4. 



Velutina otis, Auct. 



Animal suboval, auriform, thick, pure white. The mantle 

 does not extend beyond the shell, and 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 furnished 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 prominences 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 precisely similar to that of 

 Otina otis. The doubtful branchial plume lies under the 

 centre of the mantle, evidenced by apparent pectinations, but 

 the exact form escaped observation. The animal is not more 

 than -jVth or -^th of an inch in diameter ; yet there is not a 

 point mentioned that admits of doubt, except the precise 

 structure of the branchial organ. There is no operculum. 



This animal is found at the roots of the Lichina pygmaa, 

 on rocks about three miles east of Exmouth, often in com- 

 pany with Kellia rubra. When the animals were placed in 

 basins of water they always made their way out of them, and 

 fixed themselves to a dry spot, as is the case with many of 

 the Littorinae, which almost constantly live in free air. This 

 curious and anomalous creature is entirely dissimilar to Velu- 

 tina, and its natural position is far removed from that genus 



