The common limpet is a specially interesting and abundant example of the more primitive Aspidobranchia.
Ab, g, The limpet breeds upon the southern English coast in the early part of April, but its development has not been followed.
The foot of the limpet is a nearly circular disk of muscular tissue; in front, projecting from and raised above it, are the head and neck (figs.
The eyes of the limpet deserve mention as examples of the most primitive kind of eye in the Molluscan series.
At low tide the limpet (being a strictly intertidal organism) is exposed to the air, and (according to trustworthy observers) quits its attachment and walks away in search of food (minute encrusting algae), and then once more returns to the identical spot, not an inch in diameter, which belongs, as it were, to it.
- Dorsal surface of the Limpet removed from its shell and deprived of its black pigmented epithelium; the internal organs are seen through the transparent body-wall.
Thus, then, we find that the limpet possesses a symmetrically disposed pair of ctenidia in a rudimentary condition, and justifies its position among Aspidobranchia.
It is probable that the limpet takes several years to attain full growth, and during that period it frequents the same spot, which becomes gradually sunk below the surrounding surface, especially if the rock be carbonate of lime.
40), in which the margin of the mantle-skirt coincides, just as it does in the limpet, with the margin of the shell.
- Anterior portion of the same and opening on the right Limpet, with the overhanging cephalic shoulder, so to speak, of hood removed.
Truncatulus harbours the Cercaria of Fasciola hepatica, the liver-fluke, which causes rot in sheep. Ancylus, which occurs in rivers, has a minute limpet-like shell.
- The Common Limpet (Patella vulgata) in its shell, seen from the pedal surface.
Limpet, and that of the g ' nerves which pass from the visceral loop of Haliotis to the olfactory patch or osphradium, which lies in immediate relation on the right and on the left side to the right and left gill-plumes (ctenidia) respectively.