RISSOA. 375 
group, but if observed attentively, it will often assume the 
more pointed termination of the Risso@; it is also, as in 
them, a little constricted below the. anterior end, and has on 
the sole a slight, mesial, longitudinal depressed line. 
The next species is the so-called Cerithium reticulatum, but 
as there is already in the Rissoidean list the R. reticulata of 
Montagu, the specific title should be changed: it is proposed 
to substitute vulgatissima, an appellation of great significancy 
in respect of this animal. 
** KHlongato-turrita. 
R. vuieatissima, nobis; Da Costa. 
Cerithium reticulatum, Auct. 
———, Brit. Moll. iu. p. 192, pl. 91. f. 1,2; (animal) 
plat. f..2. 
Murex reticulatus, Mont. 
Animal occupying an elongated dark brown shell of 10-12 
spiral volutions, furnished with close-set costellee and spiral 
striz, which, at the pomt they cross the riblets, exhibit the 
moniliform sculpture of four points on each. Mantle plain, 
forming a small dilatation to correspond with the shell. The 
head is rather a long muzzle, anteally vertically cloven, and 
marked with nearly black, thickly-set transverse bars. The 
buccal apparatus is strictly Rissoidean, composed of a pair of 
jaws and lingual riband, which are perfectly white, supported 
by pmkish corneous plates, which can, through the tenuity of 
the under part of the muzzle, be seen in action, as in the 
Rissoe. The animals are very voracious ; we observed many 
sucking in ropes of molluscan mucus with great gusto and 
avidity. The tentacula are rather strong and short, not very 
pointed, yellow, and irregularly aspersed with flake-white and 
lead-coloured blotches. Eyes on distinct but very short 
pedicles at the external angles. The foot is rather short, 
truncate in front, very slightly auricled, and constricted 
anteally, but well labiated, and tapers to a moderately-pointed 
termination; on the upper surface pale yellow, mixed with 
darkish smoke-coloured poimts; on the under part, or sole, 
with longitudinal patches on each side of the palest lead-colour, 
