CATALOG OF THE FOSSIL FISHES IN THE CARNEGIE MUSEUM. 393 



Order PLAGIOSTOMI. 



Suborder SELACHII. 



Family CESTRACIONTID^. 



Genus Cestracion Cuvier. 



"To this existing genus, commonly known as the Port Jackson shark, have 

 been referred certain skeletal remains, not as yet satisfactorily distinguished from 

 it, which occur in the Lithographic Stone of Bavaria. The type-specimen, upon 

 which the so-called 'Acrodus falcifer' Wagner (= Cestracion) was founded, is 

 preserved in the Paleontological Museum at Munich, and other imperfect portions 

 of the skeleton are to be seen in the British Museum. None, however, exhibits 

 the entire outline and fin-characters at all satisfactorily."'^ 



1. Cestracion falcifer Wagner. 



(For references to the literature prior to 1911 cf. A. S. Woodward, Cat. Foss. 



Fishes Brit. Mus., Pt. I, p. 332.) 

 1911. Cestracion falcifer C. R. Eastman, Amer. Journ. Sci. (4), Vol. XXXI, p. 400. 



"The typical example of this species shows everj^ indication of being an adult 

 individual and is estimated to have had a total length of about 40 cm. In it the 

 two dorsal fin-spines are seen to be of unequal size, both are slightly recurved, 

 and that of the anterior dorsal is inserted at a point about midway between the 

 origin of the pectorals and posterior dorsal fin. It would appear from the pub- 

 lished figures, also, that the pelvic pair arises opposite the first dorsal; and the 

 shagreen granules are described as ' schaufelf ormige oder kornelige,' without being 

 markedly differentiated in size. 



"To this species has been referred by von Zittel (loc. cit., p. 77) a well pre- 

 served smaller individual, the total length of which is only 12.5 cm., or less than 

 one-third of that of the type. According to the same author this smaller speci- 

 men, which he regards as the young of C. falcifer, has feebly striated lateral teeth, 

 and is provided with enlarged stellate tubercles in the dorsal region. The descrip- 

 tion of this feature reads : ' Neben den schaufelformig gestalteten Chagrinschuppen 

 liegen in der Riickenregion kurze gekriimmte Stacheln, welche sich auf einer 

 vierstrahligen Basis erheben.' 



"It cannot escape notice that the smaller example just referred to presents 

 characters in common with the well-preserved specimen in the Carnegie Museum 

 from the same horizon and locality, immediately to be described as the type of a 



s Eastman, C. R., Am. Jour. Sci. (4), Vol. XXXI, p. 400. 



