492 MURICID i. 
cula. IT can say nothing of the branchial plume and reproduc- 
tive organs, being unwilling to make a perhaps useless attempt 
to see them by the destruction of the beautiful specimens. 
This very elegant creature inhabits the middle levels of the 
littoral zone at Exmouth, in quiet sheltered pools amongst the 
minor Algz, in company with the Cerithium reticulatum, (our 
Rissoa vulgatissima,) which outnumbers it by fifty to one. 
With it is also rarely found the Murex adversus of authors, 
which we believe, when the animal is seen, will prove to be 
congeneric with Rissoa vulgatissima.. When our present animal 
is just captured it is very lively, and creeps up a glass quickly. 
There can scarcely be a greater contrast than between this 
animal and that of the Rissoa vulgatissima, with which it has 
hitherto been confounded, and which has the entire aspect of 
an elongated Rissoa, whereas our Murex tubercularis is an 
undoubted Canalifer, though it has evident relations with 
Eulima and Chemnitzia by the position of the eyes and shape 
of the tentacula; still the balance of characters is greatly in 
favour of the present position. I believe Mr. Alder and 
myself are the first and nearly contemporaneous observers of 
this species. 
We believe the Cerithium metula of the ‘ British Mollusca’ is 
congeneric with Murex tubercularis above. But it is pos- 
sible it may not be a muricidal animal: if so, it will probably 
fall into the section of the elongated Rissoe. 
?M. metuta, Loven. 
Cerithium metula, Loven. 
, Brit. Moll. i. p. 198, pl. 91. f. 3,4. 
Sectio VII.—Testa gracilis, fusiformis, plicata, spiraliter striata. Canalis 
effusus. Apertura subovalis, labio externo plus minusve emarginato. 
Columella planato-substriata. Operculum nullum. 
Manee ia, Leach, Forbes and Hanley. 
M. eracizis, Montagu et auctorum. 
Mangelia gracilis, Brit. Moll. iii. p. 473, pl. 114. f.4; (animal) 
pl. R.R. f. 8. 
Animal spiral; ground-colour white, aspersed throughout 
