at Maldonado, in a lake that had been suddenly drained. There are three specimens
in the collection, none of them exceeding the length above given. Mr.
Darwin, however, states in his notes, that he believes them to be full grown,
having taken them so repeatedly, in brooks, of the same size. The number of
spots varies from nine to twelve, and is sometimes different on the two sides of the
same specimen.
Independently of the spots, which at once characterize this species, it is
readily distinguished from the last by its teeth, which are more cutting than pointed,
and in this respect rather departing from the character of the genus as established
by Valenciennes.
1. L e b ia s ' l i n e a t a . Jen.
P l a t e X X II. Fig. 2.
L . corpore sxihelongaio, suhcompresso, viridescenti-fusco ; lateribus lineis circiter
septem longitudinalibus nigris, e maculis parvis subconflueutibus formatis : dentibus
uniseriatis : caudali rotundatâ.
D. 9 ; A. 9; C. 26, brevibus inclusis ; P. 13; V. 6 .
L o n g . u n c . 1. lin . 10.
F orm.— G eneral form very similar to that of the Poecilia decem-maculata. Slightly compressed ; the
depth one-fifth of the len gth; the length o f the head about four-and-a-half times in the
same. H ead depressed : snout obtuse: mouth sm all; the commissure horizontal. U pper jaw
very protractile ; the lower one rather the longest, when the m outh is shut. T eeth forming
a single closely-set series, somewhat compressed at bottom, the cutting edges tricuspid.
Diam eter of the eye nearly one-fourth tbe length of the head. Some large conspicuous pores
on the lower jaw, passing upwards in a series along the margin o f the preopercle, not very
near together, about eight or nine in all.
Scales large, covering the head and all the pieces of the gill cover, as well as the body.
About eight in the depth, and thirty In a longitudinal line from the gill to the caudal.
One taken from the middle o f the side of a semi-elliptic somewhat oblong form ; the free
portion very finely striated, the basal with ten or twelve deeper-cut striæ , these last nearly
parallel, and of equal lengths. L ateral line faintly marked out by a dotted line ; the first
half in the third row of scales from the top, the last half in the fourth row.
Dorsal commencing at exactly the middle point of tbe entire length. A nal opposite and
similar. C audal rounded. Pectorals small, about tw o-thirds the length of the head. V entrals
smaller, barely one-half of the same. T he pectorals, when laid back, reach to the insertion of
the ventrals ; but the latter hardly attain to the anal.
C o lo u r . — Greenish-brown, with six or seven longitudinal dark lines on the sides, the lines apparently
made up of spots for the most part confluent, but here and there not so, interrupting the
continuity of the lines. All the fins pale dusky, without any spots or markings.
Habitat, Maldonado.
This new species of Lebias was taken by Mr. Darwin in the same lake at
Maldonado with the Pcecilia decem-maculata. There are several specimens in the
collection, none of them exceeding the size above mentioned, and they have all
the appearance of being full grown. Some have the lines of spots much more
interrupted than others.
2 . L e b ia s m u l t i d e n t a t a . Jen.
P l a t e X X II. Fig. 3 .
L . corpore subelongato, subcomjiresso, viridescenti-fusco ; lateribus fa sciis angustis
paucis longitudinalibus albidis ohscurioribus : dentibus seriebus plurim is dispositis,
omnibus tricuspidatis : caudali rotundatâ.
D . 9 ; A. 9 ; C. 26, brevibus inclusis ; P . 13 ; V. 6 .
L o n g . u n c . 3. lin . 2.
F o rm .— The general form and proportions of this species are extremely similar to those of the last;
but it differs very remarkably in having behind the anterior row of tricuspid teeth, a band of
minuter teeth above and below, all of which are also tricuspid, and similarly formed to those
in front. Plead one-fifth of the entire length; flattened on the crown. Jaws nearly equal;
upper one very protractile. Scales large ; about thirty-two in a longitudinal line, and eight
in the depth ; covering all the pieces of the opercle ; similar in form to those of the last
species, but with the striæ on the free portion finer and more numerous, the deep-cut basal
striæ also rather more numerous, amounting to about fourteen, and of unequal lengths, gra^
dually increasing from the outermost to the middle ones. Lateral line similar; also the same
pores on the lower jaw. Fins and finray-formula similar: in both species the first and last rays
of the dorsal and anal are simple, aud shorter than the others. The anal perhaps terminates
a little nearer the caudal than the dorsal does.
C o l o d e .— (A spirits.) Greenish-brown, with very little appearance of markmgs in its present
state. There is, however, some indication of an irregular scattered row of small black spots
on each side, a little below the ridge of the back ; also of two or three pale longitudinal narrow
bands along the middle of the sides, which were probably more conspicuous in the living fish.
The belly is yellow, and very tumid ; but these are evidently characters merely indicative
of the female sex.
Habitat, Monte Video.
This is another new species of Lebias taken by Mr. Darwin in fresh-water
at Monte Video, if indeed it strictly belong to the genus ; but the circumstance
of the teeth being in several rows, and in fact forming a complete band, is at
variance with the generic characters as given by Cuvier. The teeth however
being exactly of the same form as in the other species, and the general characters
on the whole similar, Î have not thought it expedient to erect it into a new
genus. There is but one specimen in the collection, which appears to be a large
female big with young.
a