202 W. HAROLD LEIGH-SHARPE 
SCYLLIUM CANICULA 
The small spotted dogfish or rowhound ((.e., rough-hound) 
This species, smaller than S. catulus, does not differ from the 
latter, except in the matter of trifling detail (fig. 2). The 
rhipidion is so reduced as to be practically negligible; while 
12 
10 
cm. 
Fig. 2 Scyllium canicula. A., apopyle; H., hypopyle; S., siphon; S.7’., 
siphon tube; Rh., rhipidion. 
there is no doubt whatever that the siphon of the living animal 
contains sea-water, the presence of parasites adhering to the 
muscular walls within the cavity would go far to prove the 
matter. Howbeit, though I have examined some hundreds of 
S. canicula from all parts of the English Channel, from Ply- 
mouth, Bournemouth, Brighton, and elsewhere, I have not as 
