FISH. 
2. MESITES ALPINUS. Jen. 
M. viridescenti-fuscus, dorso saturatiore ; hoc, et lateribus, et pinnis, nigro levissime 
trroratis, immaculatis ; ventre niveo ; oculis majusculis. 
DE NOs AG 16:2 CxIG. Se. sez oise Vance 
Moncoune:.2. lintro: 
Form.—Very little difference in form between this and the last species. The eyes, however, are 
decidedly larger, measuring in diameter one-third the length of the head. ‘The head itself 
also appears somewhat longer, being nearly one-fifth of the entire length. The anterior teeth 
on the tongue do not seem much larger than the others. Fins similar. 
Cotour.—(In spirits). Greenish brown, deepening in tint at the top of the back. Back, sides, 
and fins, immaculate, but thickly powdered with minute dark specks, scarcely visible except 
under a lens, These specks give the fins a more dusky appearance than they possess in the 
last species. The belly appears to have been white. 
A second specimen does not differ from the above in any respect, except in being rather 
smaller, and scarcely more than two inches in length. 
Habitat, Tierra del Fuego. 
This species was taken by Mr. Darwin in alpine fresh-water lakes in Hardy 
Peninsula, Tierra del Fuego. I have no hesitation in considering it distinct from 
the last, as there are two specimens exactly similar, both shewing a larger eye, 
and an entire absence of all approach to spots; while the whole surface of the 
back and sides is thickly irrorated with dark specks, a character which does not 
appear in the plain varieties of the M. maculatus. 
3. MEsITES ATTENUATUS. Jen. 
Prate XXII. fig. 5. 
M. viridescent--fuscus, ventre vix pallidiore ; dorso, et lateribus, pinnarumque radiis, 
sparsim nigro levissimé trroratis, immaculatis : corpore pregracilt, antice attenuato ; 
capite et oculis minoribus. 
Dit: Al: C..1G, &ees Pe 125 Vor 
Lone. unc. 2. lin. 6. 
Form.—Rather more slender than either of the last two species, the body more attenuated ante- 
riorly ; the head also smaller, though scarcely shorter. Mouth and eyes both smaller; the 
diameter of the latter not more than one-fourth of the length of the head. Teeth also rather 
more minute as well as more numerous. The fins are similar, except that the ventrals appear 
to stand rather more forward, being attached exactly in the middle of the entire length, ex- 
cluding caudal: the distance from their insertion to the commencement of the anal is more 
than twice their own length. The outer rays of the caudal are worn, but there was probably 
a shallow notch when entire: the short accessory rays are very numerous, and form a very 
distinct fringe along the upper and lower edges of the fleshy part of the tail, 
R 
