MURICIDA. 1 8 be 
Shell when young free, resembling Rapana ; when adult, some- 
times with more or less irregular solid shelly extensions of the 
outer and inner lips, which clasp the axis of coral or the surface 
of neighboring shells, and at length close the mouth with the 
exception of the anterior siphonal canal which is converted into 
a Shelly tube. No operculum (7). 
We do not know how many of the species allied to the type 
of the genus may partake of this singular mode of growth; it 
has only been observed in &. antipathicus (xliv, 33,34). A large 
number of species have been grouped by Messrs. H. and A. 
Adams in a subgenus Coralliophila, the character of which is, 
that they do not (are not known to) form this shelly enclosure. 
If this supposed difference of habit should be proved by obser- 
vation, there can be no doubt that the two groups should be 
generically separated. It may be remarked that no lingual 
denticles have been found in the animals of Coralliophila, Lepto- 
conchus or Magilus examined by Troschel. Coralliophila 
possesses an operculum; I do not know whether the younger 
stage of Rhizochilus has one or not, but the presumption is that 
it has not. 
CORALLIOPHILA, H.and A. Ad. (See remarks above.) A large 
number of specific forms have been described, many of which 
have not been figured. Judging from the extreme variability 
of the well-known species both in form and sculpture, it may be 
anticipated that most of the more recently characterized species 
will prove to be synonyms. A. neritoidea (xlv, 49). 
GALEROPsIS, Hupé. I venture to place under this name the 
Rhizochilus madreporarum, Sowb. (xliv, 35), which possesses 
differential characters from both Rhizochilus and Coralliophila. 
The young shell is free, and not unlike a Coralliophila, and in 
this stage it has a small, thin operculum with lateral nucleus. 
The animal has a short siphon which scarcely projects beyond 
the canal. It is sluggish in its movements. As it matures it 
becomes attached to the coral, on which it lies and adheres with 
great tenacity, often allowing the foot to be torn away before 
releasing its hold. The conformation of the lip corresponds 
exactly with the irregularities of the place of adhesion. Upon 
removing the animal, scars will be noticed on the coral, more or 
less worn by the abrasion of the shell,and old specimens will be 
found to have deposited a shelly base. When removed, the 
animal is very timid and never wholly expands. It can only 
partly withdraw behind the columella-shelf, leaving a portion of 
the mantle and foot exposed. The foot is small, of an oval form, 
thick and fleshy. The tentacles rapidly taper to a fine point, on 
which the eyes are sessile a little beyond the middle of their 
length. The foot is tinged with pale orange, dotted with white 
along the upper margins. The mantle is colorless centrally, 
