LEPTON. 75 
malacological considerations, can belong to no other family 
than the Arcade. 
LEPTON, Turton. 
L. seuamosum, Montagu. 
L. squamosum, Brit. Moll. ii. p. 98, pl. 36. f. 8,9; and (animal) pl. O. 
£.6: 
Solen squamosus, Auct. 
Animal inhabiting a very flat, subrhomboidal, white, porcel- 
lanous, punctured shell; its ground colour is a clear white. 
The mantle is very large, having the margims sinuated, often 
puckered into two or three folds at the will of the animal; 
they extend beyond the shell more than one-third of the ver- 
tical measure at its centre, from which springs a row, on each 
side the middle of the ventral range, of twenty-five rather 
long, slender, milk-white tentacular pointed filaments; but 
the mantle thus clothed is only protruded largely beyond the 
shell, from the middle of the anterior side, throughout the 
ventral range, to the same level as the posterior end; from 
these points to the umbones it is never seen, beimg either 
closed or not protruded, but its suture or edges are furnished 
with about forty long, strong, blunt, frosted-white, rather 
close-set cirrhi varying in length; a part of these range at the 
posterior side of the beaks, above the sessile anal orifice, which 
occupies a small space without cirrhi, between the termination 
of the protrusion of the margin and the commencement of the 
larger filaments on the broader, larger, and posterior side; of 
that part of the filaments at the anterior side of the beaks, one 
is thicker, broader at the base, and double the length of the 
others; this is the last of the larger ones, which at one time I 
thought was tubular and might be an oviduct, but further 
examination seemed to disprove this idea. None of the fila- 
ments show much motion; the long one only, when the animal 
advanced a step, made an arcuated contraction, similar to that 
of the fore-finger in extenso when quickly brought down to the 
palm of the hand; it then resumed the straight position to 
await another step: all the other cirri are either retractile or 
contractile, separately or en masse. 
