Port Jackson Shark, Heterodontus portusjacksoni

Plate 113. Port Jackson Shark, or Bull-dog Shark, Heterodontus phillipi (now known as the Port Jackson Shark, Heterodontus portusjacksoni) found in Hobson's Bay

This shark, so famous amongst zoologist and geologists under the name of Cestracion, or Port Jackson Shark, is called the Bull-dog Shark by Victorians, from the form of the head and muzzle. No other Shark has any approach to the extraordinary structure, shape and arrangement of the teeth of this genus, which has been taken by Agassiz and Owen as illustrating in our time the European fossil genus Cochliodus of the Carboniferous Limestone formation; to which, in my opinion however, the relationship is not really close. It is common in Hobson's Bay. The stomach is filed with fragments of shells. There are only two eggs at a time, laid once a year. These eggs are very remarkable objects, not uncommon on the shore; they are conical in shape, about 6 inches long, and surrounded with two broad keels extending spirally and obliquely round the egg from one end to the other, like six turns of a broad screw; the substance is of a tough, dark brown, horny appearance. The stellated form of the shagreen is quite unlike that of any other genus of Sharks.