500 Capt, CAnM1cH AEL's Description of 
Description of Four Species o ish found on the Coast of Tristan 
| Cunha. | 
1. Cnæronon MoNoDACTXLUS, subolivaceus dorso transversim 
nigro fasciato, spinis 
elongata. 
Length eighteen inch 
front sloping; mout 
teeth subulate, crow 
ing to a single row 
G. plates scaly; 
part fleshy and. 
rayed ; six lo 
the bottom tw 
lar consideral j 
fleshy, and sca 
oval, compressed. Head sharp; 
ictile ;-Jij S flesh ys; jaws equal; 
e fore part of. the jaws, diminish- 
Eyes large; iris amber-coloured. 
l -rayed. Dorsal fin 17-24, soft 
- = Pectoral fan-shaped, fifteen- 
rest. bifid ; the sixth ray from 
e others. Ventral 1-5, triangu- 
ine-of the pectoral fin. Anal fin 
.9-12, the second ray very strong. 
smooth. L. line parallel with the 
| olive to bronze, with six broad, ob- - 
scurely-marked across the back, reaching half-way - 
down the side: lackish ; pectoral, amber-coloured, ex- 
tremely delicate. t : 'o ex | 
This fish is very mmon on the coast of Tristan da Cunha, and 
feeds on the leaves of the Fucus pyriferus, such of them especially 
as are covered with serpulæ. It takes the hook freely. 
I have called:this fish Chetodon, as coming nearer to that genus 
than to any other that I am acquainted with. | Among Forster’s 
drawings in the collection of Sir Joseph Banks, a figure of it is 
given under the name of Sparus Carponemus; but the form and 
disposition of the teeth exclude it from that genus. The specific 
name was suggested by the uncommon form and length of the 
| fifth 
i 
