1872.] MR. A. GARRETT ON POLYNESIAN MITRIDJE. 839 



7. List of Species of Mitridee collected at Rarotonga, Cook's 

 Islands, with Notes, also Descriptions of new Species. 

 By Andrew Garrett, of Tahiti. 



[Eeceived August 12, 1872.] 



1. Mitra episcopalis, D'Argen. 



This species occurs abundantly at all the Polynesian islands, and 

 is invariably found on sand or sandy mud in shallow water. 



2. Mitra pontificalis, Lam. 



This has as wide a range as the preceding, but is much more rare, 

 and occurs under clumps of coral on reefs. 



The animal is uniform creamy-white, with opaque white dots. 



3. Mitra adusta, Mart. 



This species, like the two above, is found at all the Polynesian 

 groups, but is comparatively rare, except at the Viti Isles, where we 

 obtained it in abundance from under stones in shallow water. 



4. Mitra ferruginea, Lam. 



Also occurs at all the South-Sea islands, and lives under stones 

 on reefs. We only found it plentiful at Tahiti and the Paumotu 

 Islands. 



The animal is cinereous, or pale yellow, slightly varied with 

 reddish brown. 



5. Mitra cardinalis, Gron. 



Has a very wide range, and delights in sandv mud, especially on 

 a stony bottom. It is not by any means abundant. Our finest 

 examples were obtained in shallow water at Tahiti. 



The animal is uniform creamy-white. 



6. Mitra fulva, Swains. 



This species is not uncommon, and has a very wide range. It is 

 found under clumps of coral on reefs. 



The animal is chestnut-brown, with a paler siphon, and white 

 creeping-disk. 



7. Mitra casta, Lam. 



A very rare Polynesian Mitra, found in sandy mud at low-water 

 mark. We only met with it at Rarotonga and Tahiti. 



8. Mitra nivea, Swains. 



This fine species is very rare. We obtained a single mutilated 

 example at Rarotonga, and four more or less perfect ones at Anaa, 

 one of the Paumotu Islands. 



9. Mitra pellis-serpentis, Rve. 



Is also rarely found, and seems to be confined to the Paumotu, 

 Tahiti, and Cook's groups. 



