Mr. Home's anatomical Account , &c. 207 
of the jaw ; but in the other parts they are less numerous. 
The teeth are small, round, conical, very pointed, and bent a 
little inwards. 
The nostrils open on the edge of the upper lip. The eyes 
are very small, and the pupils perfectly round. 
Half-way between the eye and the gills, on each side, is 
the orifice of a canal, which leads into the mouth. 
The gills are five in number on each side. 
The pectoral fins are situated a little behind the posterior 
gills. 
The dorsal fin is situated nearly opposite to the middle 
space, between the pectoral and anal fins. The posterior dor- 
sal fin is small, and situated half-way between the anal fins, 
and the setting on of the tail. The two anal fins are attached 
on their upper edge for about half their extent each to the 
lower side of a long projecting body peculiar to the male. 
All the fins have a thick round edge anteriorly, and become 
gradually thinner towards the posterior part, which is par- 
tially serrated. 
The projecting bodies on the sides of the anus I shall call 
holders, as they are employed in grasping the female in the 
time of copulation. They are rounded on their lower surface : 
the skin covering them is uncommonly thin and smooth : on 
their upper surface, it has a gloss like that of silk, and there 
is a deep sulcus, in which is contained a strong, flat, sharp, bony 
process, five inches long, which moves on a joint, and the bone 
projects an inch and a half beyond the skin, like a spur.* 
There is a deep sulcus at the setting on of the tail, as if a 
• I shall give a particular description of these holders in a future paper on the ge- 
neration of the dog-fish. 
E e 2 
