THE LARGE-SPOTTED DOG-FISH. 411 



same form as the first, but rather smaller, situated in a line over the 

 posterior portion of the anal fin, and half-way between the origin of 

 the ventrals and the end of the tail. Caudal truncated rather ob- 

 liquely, commencing low at a short distance from the second dorsal, 

 and expanding gradually towards the extremity; the anterior lower 

 lobe about twice the size of the anal fin and somewhat of the same 

 form ; the posterior lower lobe considerably smaller, of a triangular 

 form, with the apex pointing downwards. Anal fin with its poste- 

 rior extremity situated mid-way between the commencement of the 

 ventrals and the end of the tail ; ventrals in advance of the first dor- 

 sal, the lower portions not so acutely formed as in S. canicula. Pec- 

 torals broad, truncated behind ; its length considerabl}' less than the 

 space between the point of the snout and the first branchial opening. 

 The male is characterized in the same manner as in the last species. 



Mr Jenyus remarks, " (Jbrin) closely resembling the S. 

 canicula, but differing essentially in the structure of the 

 lobes of the nostrils and in the form of the ventrals. The 

 former are not united as in that species {S. canicula), and 

 of a smaller size, leaving the whole of the mouth and 

 the upper lip visible ; the ventrals, instead of being cut 

 obliquely, are cut nearly square, their posterior margins 

 meeting at a veiy obtuse angle ; they are united or se- 

 parate according to the sex in a similar manner. The 

 snout is rather more elongated, and, according to some 

 authors, the tail rather shorter, giving the dorsal a more 

 backward position ; but this last character I have not noticed 

 myself" 



The two species now before me (5'. canicula and S. catulius), 

 differ in other characters besides those above pointed out 

 by Mr Jenyns. In S. canieula, the whole of the second 

 dorsal fin is behind the anal ; in S. catulus it is in a line over 

 the lower portion of the anal. In S. canicula, the small 

 lobe which is situated immediately under the outer margin 

 of the nasal valve, is of a square form ; in iS. catulus that 

 lobe is somewhat of a triangular form and about three times 

 brondor than its length, extending from the inner corner of 



