500 MURICIDA. 
M. Smiruut, Forbes. 
Mangelia striolata, Brit. Moll. iii. p. 483, pl. 114 A. f.1, 2. 
Animal spiral, inhabiting a yellowish-brown plicated shell 
of nine volutions; ground colour white throughout, thickly 
mixed with opake intense snow-white flakes, and on the 
siphon with eight or nine bright pink spots. The mantle 
is rather tumid at the margin of the aperture, and is pro- 
duced into a short, fleshy, rather open or scoop-shaped bran- 
chial fold, which, on the march, is carried somewhat beyond 
the termination of the canal; it also lines the anal sinus at 
the upper angle of the outer lip, which some authors term a 
pleurotomic scission. The head is the usual flat muricidal 
one, having at its centre the vertical fissure from which the 
ordinary armed proboscis is emitted. The tentacula are short, 
and the portions as far as the offsets, on which the large black 
eyes are fixed externally, are thick and strong, but the conti- 
nuations are exceedingly short fine filaments. 
I consider the present, of all the species I have examined, 
as that which has the eyes nearest the points. The foot is 
exactly truncate im front, and scarcely eared at the external 
angles; in repose it is puckered and rounded posteally, but 
on the march it extends to a tolerably lanceolate termination. 
There is no longitudinal line on the sole, nor trace of an oper- 
culum ; it is bevelled laterally from the long pedicled base by 
which it is fixed to the body, and also slopes from the anteal 
truncation to a sharp edge. 
The animal is rare at Exmouth, and inhabits the coralline 
zone; it is extremely free, and gives every facility for exam1- 
nation; it scarcely differs from M. attenuatus, or the type, 
M. gracilis. 
It appears that the Murices of this section, none of which 
much exceed an inch in length, are all without opercula, and 
have erroneously been considered the Pleurotomata of La- 
marck, who constituted the genus Clavatula for some of the 
species, but afterwards abandoned it. The true Plewrotomata 
have all a deep sinus or emargination in the upper angle of 
the outer lip of the shell, and a corresponding scission in the 
