SQUALID^. 



155 



no anal ; spiracles large ; teeth lancet-shaped, 

 diverging from the centre ; skin rough. 

 S. borealis. Fig. 227 ; -5^ n. s. 



Acanthias (Rkso). Picked Dog-fish. Two dorsals, 

 each preceded by a spine ; no anal ; skin rough, 

 with heart-shaped scales, each with a central spine; 

 several rows of teeth in each jaw. 



A. vulgaris. Fig. 228 ; ^ n.s. 



228 



Alopias (Bonaparte). Sea-fox. Two dorsals, 

 the first high, the second over the anal ; head 

 pointed; upper portion of the tail very long, 

 notched at the base. 



A. vulpes. Fig. 229 ; /^ n. s. 



Selachus (Cuv.). Basking Shark. Two dorsals, 

 wide apart ; snout short and blunt ; gill-openings 

 very large. 



S. maximus. Fig. 230 ; yItf ^- *• 



