HOLOCEPHALI 



177 



B 



,-vt 



pvt. 



si 



St. 



Fit;. 111. 



A, dentition of M\ii-w-m\.thut. B, dorsal view of Squaloraja polyspondyla, Ag. C, 

 dentition of Cattorh yiwhux ; D, of S'lualorajn ; E, of Rhynchodus ; F, of Harriotta degans. D 

 uml G, Elasmodus JIunteri, EJJJ. (All after Dean.) a.d, anterior clasper ; c, paired cartilage ; 

 t-', clasper; f.v, fused postoccipital vertebrae ; pst, ' predentary ' tooth ; pt, ' palatine' tooth- 

 1'late; pv.t, ' prevoinerine ' tooth ; r, rostrum; st, tooth-plate of lower jaw; t.n, tritoral area; 

 /(, tentaculuin ; t'.c, vertebral column ; v.t, ' vomerine' tooth. 



12 



