^P. heros^ (generally referred to as ^Lunatia^ or ^Natica heros^). One of the commonest large shells and one of the most characteristic species of the New England and New Jersey littoral fauna. It is exceedingly common along the Long Island shore, where it may be found on the open beach, in pools with a sandy bottom left by the receding tide. It is usually partially and frequently wholly buried in the sand. The umbilicus is open and large, the operculum corneous, and the shell heavy and ashy-white to brownish, with (when young) a yellowish epidermis. Its length is from two to four inches. It has no ornamentation whatever. /P. heros/ is a most voracious creature and spends its time in hunting for flesh—either alive or dead—to devour. It feeds upon dead fish, or upon other mollusks whose shell it is able to pierce by means of its radula, making a little round hole through which it sucks out the flesh from within. The curious egg-cases of this species have already been referred to. (See Plate I.) It glues together particles of sand into the form of a basin with the bottom knocked out and broken on one side. In the gelatinous substance of this basin it deposits its eggs in a regular order. These hatch out in midsummer. Egg-cases of this kind can always be found wherever /Polynices/ lives. For a long time naturalists were greatly puzzled by these curious things, and their blunders are recorded in earlier works, where these egg-cases have been elaborately described as living animals belonging to various invertebrate orders. The largest and best specimens of /P. heros/ are to be found south of Cape Cod. (Page 343.) ^P. triseriata.^ A small shell of exactly the same shape as /P. heros/, but decorated with three revolving series of bluish or chestnut spots. It is pretty well determined that this so-called species is only the young of /P. heros/. It is very abundant all along the coast. [Illustration: /Polynices triseriata/, young; /Polynices triseriata/, older specimen.]