1. U m b r i n a a r e n a t a . C u v . et Val.
U m brina areiiata, Cuv. et Val. H ist. desP oiss. tom , v. p. 141.
F orji.— R ather elongated, with the back very little arched ; the greatest depth contained aboat five
times and a quarter in the entire length. Length of the head about equal to the depth of the
body. Profile falling very gradually, and nearly in a straight line, in front of the dorsal.
Snout very much projecting ; the margin a t bottom, above the upper jaw , divided into four
lobes which are cut square at their extremities. R ound the end of the snout, and immediately
above the lobes, is a double row of pores, the lower ones large. Also four pores beneath the
symphysis of the lower jaw . Barbule a t the chin scarcely exceeding a line o ra line and a half
in length. A band of velutine teeth in each jaw , with an outer row in card; these last
moderately strong, sharp, and rather wide apart, not above fourteen or sixteen in the row.
Preopercle very obsoletely denticulated. Opercle with two flat points not much developed.
First dorsal triangular ; the first spine very sm all; the second, third and fourth elevated
rather in a point, the third equalling two-thirds of the depth of the body or more. Second
dorsal nearly twice the length of the first. Anal commencing opposite the sixth soft i-ay of
that fin, short, and term inating considerably before it; the anal spine weak, and very little
more than h alf the length o f the soft rays. C audal with the posterior m argin sinuous, the
upper part being slightly crescent-shaped, the lower portion rounded, and broader than the
upper. Pectorals a very little shorter than the head. Ventrals attached a little behind the
pectorals, and not passing beyond them. In the axilla of the pectorals is a small triangular
membranous lam ina: there is also a narrow pointed one in the axilla of the ventrals covered
with scales. The scales on the body are thin, rather small, somewhat rhomboidal, with their
free margins ciliated, and with a fan of twelve striæ behind.
B. 7; D. 10— 1/25; A. 1/8; C. 17; P. 21 ; V. 1/5.
Length 9 inches 0 lines.
C o l o u r . — “ Body mottled with silver and green: dorsal and caudal fins lead-colour.”— D .
In spirits, the colour appears dusky brown, with darker m ottlings and silvery reflections ; paler
beneath. The fins are dusky, but the basal half of the dorsal is darker than the upper. The
pectorals are darker than the other fins, especially the inside; on the left pectoral, the dark
colour is restricted to three broad transverse fasciæ. There are also on the pectorals and anal,
and on most of the scales on the body, small blackish dots, as mentioned in the ‘ Histoire des
Poissons.’
A second specimen, smaller than the above, has the back rather more arched, the greatest depth
being only five times in the length. The outer row of teeth in the upper jaw is not quite so
conspicuous, the teeth being smaller and closer-set, and consequently more numerous. The
soft dorsal and anal have fewer rays.
D. 10—1/22; A. 1/7; &c.
Length 7 inches 3 lines.
In all other respects similar to the specimen first described.
Habitat, Bahia Blanca, and Maldonado.
As Cuvier and Valenciennes have mentioned individuals of this species,
which varied in the number of rays in the soft dorsal from twenty-two to twenty-
four, I cannot but consider the two above described as specifically the same,
though in the first these rays amount to as many as twenty-five. This, which is
the larger specimen, was taken by Mr. Darwin at Bahia Blanca, where it is said
to have been common. The other was obtained at Maldonado.
2. U m b r in a o p h i c e p h a l a . Jen.
U. elongata; rostro ohhisissimo, tumido, haud ultrà fauces producto, margine inferiore
qaadrilohato, lohis intermediis rotundatis ; fossuU longitudinali inter nares,
profundé exaratá; poris quatuor infra symphysin; dentibus velutinis, serie exlerná
in maxillá superiore aculeiformi; preoperculo obsolelè denticulato; operculo mucronibus
duobus parvis instructo ; spinis dorsalibus tertiâ et quartá longissimis,
corporis altitiidinem esquantibus ; spina anali gracili, radiis articulatis dimidio
breviari.
D. 12—1/22; A. 1/9; C. 17; P . 20; V. 1/5.
L ong. unc. C. lin. 5.
F orm.— Very much elongated; the greatest depth ju st one-sixth of the entire len g th ; the head
one-fifth. Dorsal line nearly straight. Profile falling very slightly till it reaches the nostrils,
when it suddenly becomes vertical. Snout in consequence short, and very blunt, and not projecting
beyond the jaw s ; with a deep broad channel down the middle, extending from between
the nostrils to near the m o uth : on each side of tliis channel, the snout is very protuberant.
The lower margin of the snout is divided into four lobes, the central pair of whicli are rounded :
above each o f the exterior lobes is one large pore, and an odd one in the middle. There are
also four pores beneath the symphysis, and a short barbule, as in the last species. The eye
has a diameter about one-fifth the length of the head, and is distant one diameter from the
end of the snout. The nostrils, which are immediately in advance of the eye, consist o f two
round apertures, one before the other, the posterior one double the size of the anterior. Upper
jaw a very little longer than the lower. A band of velutine teeth in each jaw ; with an outer
row above of moderately strong card, rather curving inwards and backwards, and closer-set
than those of the U. arenata, amounting to twenty-eight or thirty in n um b er: there are also
some smaller card teeth behind this outer row passing insensibly into the velutine. Preopercle
very obsoletely denticulated. Opercle with two flat points not very obvious.
First dorsal triangular, and moderately high in the p o in t; third and fourth spines longest,
about equalling the depth of the b od y; first spine very small: all the spines rather slender.
Second dorsal about h alf as long again as the first, but the rays are too much broken to judge