OF NEW SOUTH WALES. 307 



or spirit preserved specimens admitted. But all who have 

 studied the Anatomy of Fishes, as indeed of most of the verte- 

 brates, must have ascertained that a true knowledge of an 

 animal can only be attained by its examination in a perfectly 

 fresh state. It is in this view that Baron M.-Maclayhas occupied 

 himself, 'during his stay here for the benefit of his health, in the 

 continuation of his study of the Brains of the Sharks and Rays,* 

 a species of investigation, which, above all others, requires the 

 supply of fresh specimens. 



While chiefly directing his attention to the Brain, the Baron 

 has, at the same time, made such notes and illustrations of the 

 o-eneral appearance and anatomy of the different species as 

 seemed desirable or necessary to fill up gaps in their history. 



The share I take in this paper is at the Baron's request, to 

 identify and describe the species to which his anatomical details 

 apply ; and if in doing this, I appear, in some instances, to be 

 re-describing species already well known, it is because I have 

 found that even for the most simple specific characters, dried 

 specimens cannot be relied upon ; and I am anxious to take 

 advantage of this opportunity to give careful and correct des- 

 criptions from living subjects. 



As the subject proposed in the heading of this paper is an 

 extensive one, and the Baron's work will proceed in whatever 

 direction specimens may be procured for dissection, these papers 

 will not appear in any particular order, and consequently, any 

 remarks as to classification, &c., must be reserved to the last. 



This paper will be limited to the Family of Heterodontid^, 

 the Cestraciontid^, of Qunther, Gat. Fish, Brit. Mus., vol. YIII, 

 p. 415. 



For many years it was believed that the only living repre- 

 sentative of this once numerous family of sharks was the fish 

 so well known as " The Port Jackson Shark." And though 

 other species have since been found in other parts of the Pacific, 

 it may still be looked upon as almost exclusively an Australian 

 group. The period of their existence in other parts of the world 

 is long since past. 



* Vide Ji. von Mikluho-Maclay Baitrage zur Vergleichendur Neurolozie der Wirbel- 

 thiere. Th. 1 and 2. Leipzig, 1870. 



