110 GLAUCUS ; OR, 
earth-worm ; not ringed, though, like the earth-worm, 
but smooth and glossy, dappled with darker spots, 
especially on one side, which may be the upper one. 
Put round its mouth twelve little arms, on each a 
hand with four ragged fingers, and on the back of 
the hand a stump of a thumb, and you have 
Synapta Digitata (Plates IV. and V., from my draw- 
ings of the live animal). These hands it puts down 
to its mouth, generally in alternate pairs, but how 
it obtains its food by them is yet a mystery, for 
its intestines are filled, like an earth-worm’s, with 
the mud in which it lives, and from which it 
probably extracts (as does the earth-worm) all 
organic matters. 
You will find it stick to your fingers by the whole 
skin, causing, if your hand be delicate, a tingling 
sensation; and if you examine the skin under the 
microscope, you will find the cause. The whole skin 
is studded with minute glass anchors, some hanging 
freely from the surface, but most imbedded in the 
skin. Each of these anchors is jointed at its root 
into one end of a curious cribriform plate——in plain 
