A. Smith Woodward — On the Genus Notidanus. 211 



were thus somewhat problematical, but the distinguished palgeon- 

 tologist just mentioned felt justified in regarding it as the type not 

 only of a new species, but also of a new genus. Some years later, 

 when preparing his classical work on Fossil Fishes, Agassiz con- 

 firmed Minister's original determination, and founded a second species 

 of Aellopos — termed A. Wagneri — upon another specimen preserved 

 in the Munich Museum. This likewise exhibited only the hinder 

 region of the body, but the great relative size of what was then 

 considered to be the second dorsal fin, and the distinctly calcified 

 vertebral rings, were quite sufficient to separate it from all fossil 

 sharks at that time known. No figures were published, however, 

 and Agassiz' short notice embodied all available information until 

 1861, when Dr. Andreas Wagner was engaged in investigating the 

 fish-fauna of the Solenhofen Stone, and succeeded in elucidating the 

 problematical fossil by a reference to the magnificent specimen of 

 Notidanus eximius, figured by Beyrich and Frischmann. His re- 

 searches led to the conclusion that Minister's A. elongatus was really 

 a Squatina (or an allied genus), and that Agassiz' A. Wagneri might 

 be referred with equal certainty to the genus Notidanus. The con- 

 siderable dimensions of the supposed " second " dorsal fin were thus 

 no longer remarkable, and the comparatively advanced condition of 

 the vertebral column was recognized as quite similar to that of the 

 complete specimen just quoted. Some minor differences are sufficient 

 to distinguish N. Wagneri from N. eximius, and among others, may 

 be mentioned the relatively greater length of the dorsal fin : the 

 vertebra? are also longer, and wide interspaces between them do not 

 begin to appear before the middle of the tail, whereas in N. eximius 

 this character is obvious quite at its commencement. 



5. N. intekmeditjs, Wagner. 

 1861. iV. intermedins, A. "Wagner, loc. eit. p. 299, pi. iv. fig. 3. 



A species founded upon a single tooth from the Lithographic Stone 

 of Muhlheim, near Solenhofen, and characterized by the large size of 

 the denticulations in front of the principal cone, which is thus placed 

 not far in advance of the middle of the tooth. Behind the principal 

 cone are five smaller ones. 



As Wagner observes, this determination is merely provisional, for 

 the dentition of N. Wagneri is at present wholly unknown, and the 

 form of tooth in question may eventually prove to belong to the 

 latter species. 



6. N. Htjgeli^e, Miinster. 



1843. N. Eiigelice, Graf von Miinster, " Beitrage zur Petrefaktenkunde," pt. vi. 



p. 54, pi. i. fig. 5. 

 1852. ,, „ (?) F. A. Quenstedt, "Handbucb. der Petrefaktenkunde," p. 



167, pi. 13, figs. 5, 6. 

 1858. ,, ,, F. A. Quenstedt, " Der Jura," p. 519. 



This species was founded by Miinster upon a broken tooth from 

 the Corallian of Gammelshausen, near Boll, Wurtemberg. The 

 specimen exhibited a large principal cone (without anterior serrations) 

 followed by two small cones of about one-third the size of the first. 



