4 49 
Structure and 0 economy of Whales. 
D. The opening of the vagina. 
E. The anus. 
Fig. 2. The fulcus, in which the left nipple lies, fpread open, 
and the nipple itfelf expofed to view. 
Fig. 3. The lulcus of the right nipple, in a natural Fate, 
only appearing like a line. 
Fig. 4. A lulcus near to the nipple, which is fpread open to 
fliew the infide. This fulcus, I conceive, gives a freedom to 
the motion of the Ikin of thefe parts, fo as to allow the nipple 
to he more freely expofed. 
Fig. 5. The fame fulcus on the oppofite fide, clofed up. 
PLATE XXII. 
A fide view of one of the plates of whalebone of the Ba- 
laena Roftrata. 
A. The part of the plate which projects beyond the gum. 
B. The portion which is funk into the gum. 
CC. A white fubftance, which furrounds the whalebone, 
forming there a projecting bead, and alfo pafling between the 
plates, to form their external lamellae. 
DD. The part analogous to the gum. 
E. A flefby fubftance, covering the jaw bone, and on which 
the innerftamella of the plate is formed. 
F. The termination of the plate of whalebone in a kind of 
hair. 
PLATE XXIII. 
Fig. .. A perpendicular feCtion of feveral plates of whale- 
bone in their natural iituation in the gum ; their inner edges, 
or fhorteft terminations, are removed, and the cut edges of the 
plates feen from the infide of the mouth. 
R r r 2 
The 
