100 CATALOG OF FOSSIL FISHES IN THE MUSEUM 



A restored outline showing the plates in natural relation 

 to each other is given in figure 34. 



Onondaga limestone (Mid Devonic); Williamsville, 

 N. Y. Collected by Dr. Richard Rathbun. 



E 2401 A rectangular plate with attached spine, on a piece of lime- 

 stone; shown in outer view. The plate is mostly 

 weathered away, but in places where it is preserved, 

 it is seen to have an ornamentation of dots running into 

 lines which are more or less parallel to one another and to 

 the outer margin of the plate. An interesting feature of 

 the specimen is the fact that the core of matrix of the 

 proximal half of the spine seems to preserve the thickness 

 of the spine in life (fig. 35). So far as we are aware, this is 



Fig. 35. Acanthaspis armata Newberry. Cross-Section of Spine 

 The shaded area is the central cavity infiltrated with matrix; natural size. E 2401 



the first specimen of Acanthaspis to be found which clearly 

 shows the section of the spine. This is elliptical and 

 rather thicker than is generally supposed, the shorter 

 diameter of the section being two-thirds the longer. 



The specimen agrees pretty closely with specimens of 

 Acanthaspis from the Delaware limestone of Ohio, and 

 although the ornamentation of the plate is rather more 

 linear than is usual in these elements, still it seems to us 

 referable to the typical species, Acanthaspis armata. 



Onondaga limestone; Leroy, N. Y. Collected and 

 presented by Prof. C. J. Sarle. 



Acanthaspis sp. 



E 2013 A detached spine (PI. 28, fig. 4). It is of the usual form of 

 the distal half of the spines of Acanthaspis armata, and 

 somewhat triangular in cross-section. It bears a few 

 scattered tubercles, and on the inner surface, parallel 

 incised lines. 



Conodont bed (Lower Genesee) ; Eighteen Mile Creek, 

 North Evans, near Buffalo, N. Y. Collected by W. L. 

 Bryant. 



