418 MEMOIRS OF THE CARNEGIE MUSEUM. 



Teeth are not preserved in either of the containing slabs which display nearly the 

 entire body of the fish, but are found associated with some of the opercular plates 

 and jaw-parts which have been fractured off from the main portion of the fossil, 

 the whole mass being embedded in a separate block of limestone which evidently 

 lay in juxtaposition with the two larger slabs.* It is difficult to identify all of 

 the plates which are found partly overlying one another and forming a more or 

 less confused mass in this smaller block of limestone, but it is evident at a glance 

 that other elements bordering the mouth-cavity besides those in direct relation with 

 the jaws were dentigerous. Small, recurved conical teeth were probably borne on 

 the entire palatal roof, including the pterygoids and parasphenoid, and some may 

 have lined the throat cavity, as is perhaps to be inferred from the occurrence of 

 numerous small conical teeth in clusters, which show no signs of havingbeen em- 

 bedded at the base in alveolar sockets and can scarcely be considered as jaw-teeth. 

 As regards form and mode of occurrence, the teeth just described agree closely 

 with the conditions noted by Vetter in two individuals of the type-species studied 

 by him. This will appear from the following passage which is extracted from the 

 account of the dentition of A. titanius given by the author just named. ^^ 



* Since Dr. Eastman wrote these lines the Director has had the specimens carefully examined, 

 with a view to ascertaining possible points of contact between the pieces embedded in the plaster mount. 

 This work was very carefully done by Mr. O. A. Peterson. It is now discovered that the upper caudal 

 lobe of the specimen in both slabs is very ingeniously made out of plaster of Paris. Whether it is 

 possibly a cast made from fragments, which were not preserved, and for wliich this plaster of Paris 

 reproduction was substituted, it is not now possible to say. The examination made shows that, as 

 restored by the original collector, he was careless in noting the contacts, with the result that the lower 

 lobe of the caudal as placed was quite too near the vertebral column, a piece containing the fulcra evi- 

 dently having been dropped out. 



Figure 6, wliich has recently been made by Mr. Prentice, shows the exact facts as to the caudal 

 lobes. 



In reference to the head (48636) which has been associated by Dr. Eastman with the specimen, it 

 must be said that this association is not determinable by any contacts which can be discovered in the an- 

 terior parts of either of the larger slabs containing the body of the fish. All the plaster has been removed 

 and a diligent search has been made for contacts, but none are discoverable. If it belonged to the larger 

 blocks, it must have been lying at some remove from the rest of the body of the fish. There is a 

 presumption in favor of its having been a part of this specimen, arising from the color and composition 

 of the matrix. Unfortunately Baron Bayet does not appear to have always appreciated the importance 

 of preserving exact records as to the origin of specimens, and we have no clue in any list of purchases 

 made by him, or any of his correspondence, which is in our hands, which would serve to establish the 

 fact that the head and the body associated by Dr. Eastman belonged together. This association, 

 while it appears plausible, nevertheless does not rest upon evidence which is incontestable. 



W. J. Holland. 



" Vetter, Benjamin. Die Fische aus dem lithographischen Schiefer im Dresdener Museum 

 (Mittheil. K. Mineral-Geol. Museum Dresden, 1881, Pt. IV, p. 99). 



