BY W. MACLEAY, F.L.S. 355 



Port Jackson. Length six feet. Very numerous and extremely 

 prolific. 



This Fish has generally been regarded as identical with 

 Galeus cams, " The Tope" of English fishermen. I think I 

 am justified in separating them. It is the " School Shark" of 

 the Port Jackson Fishermen. 



Genus Zyg.ena, Cuv. 



The first dorsal fin opposite to the space between the pectorals 

 and ventrals, without spine. Caudal fin with a single notch. A 

 pit at the commencement of the caudal fin. Anterior part of 

 the head broad, flattened and laterally elongated. Eyes situated 

 at the extremity of the lateral elongations. A nictitating 

 membrane. No spiracles. Nostrils situated on the front edge 

 of the head. Mouth crescent-shaped. Teeth of both jaws 

 similar, oblique, with notch. 



Temporate and Tropical Seas. 



1080. Zyg.ena malleus, Shaw. 



Gunth., Cat. Fishes, VIII., p. 381. Synonyms numerous. 



" Tlie Hammer -headed Shark." 



The length of the hinder margin of one side of the hammer 

 is nearly equal to its width near the eye. Nostril close to the 

 eye, prolonged into a groove running along nearly the entire 

 front margin of the head. 



Port Jackson, Port Phillip. Length from four to eight feet. 



Genus Mustelus, Cuv. 



The first dorsal fin opposite to the space between the pectorals 

 and ventrals, without spine ; the second not much smaller than 

 the first. No pit at the root of the caudal fin, which is without 

 distinct lower lobe. A nictitating membrane. Spiracles small, 

 behind the eyes. Mouth crescent-shaped, with well developed, 



