FISH. 79 
to each other, and also to the space just alluded to. From the end of the second dorsal to the 
commencement of the caudal is exactly one-sixth of the entire length. The posterior half of 
the anal nearly answers to the second dorsal, but the two fins do not terminate exactly in the 
same line, the dorsal extending a little the furthest. Caudal forked for about half its length. 
Pectorals about two-thirds the length of the head. Ventrals attached at a point beyond the 
extremity of the pectorals. Breadth of the silver band about one-fifth the depth of the body. 
Cotour.—Not noticed in the recent state. In spirits, the back and sides above the silver band 
are brownish, with the contour of each scale marked out by black dots. All below the band 
appears to have been silvery. The band itself is not very brilliant. Both the dorsals, as well as 
the caudal, are dusky: anal and ventrals pale. 
A second specimen does not differ from the above, excepting slightly in the fin-ray for- 
mula, which is as follows: 
D. 5—1/10; A. 1/15; &e. 
Habitat, Valparaiso. 
This species was found by Mr. Darwin at Valparaiso in fresh water, in the 
month of August. It would seem to be nearly allied to the A. laticlavia of Cuvier 
and Valenciennes, brought from the same locality by M. D’Orbigny ; but, judging 
from the short description in the ‘‘ Histoire des Poissons,” it is more elongated, and 
has the head longer in relation to the depth of the body ; also has the silver band 
narrower. In the A. laticlavia, the head is said to be equal to the depth, and to 
be contained six times in the entire length ; the breadth of the silver band to be 
greater than in any other species. In the A. microlepidota, the depth is 
one-eighth and the head one-sixth of the length: the silver band not broader than 
in the A. argentinensis and some others. The colouring also of the fins appears 
different in the two species. 
3. ATHERINA INCISA. Jen. 
Prate XVI. Fig. 2. Nat. size. 
Fig. 2. b. Twice nat. size. 
Fig. 2. a. Magnified scale. 
A. gracillima; corporis altitudine partem vix nonam, capite sextam, longitudinis 
equante: oculis mediocribus: maxillis equalibus, valde protractilibus ; commissura 
primum horizontali, posterius deflexd: dentibus velutinis, in maxilla inferiore 
minutissimis: dorsali primd omnino pone ventrales reclinatas locatd: squamis 
mediocribus, seriebus longitudinalibus duodecim ad maximum dispositis, marginibus 
liberis inciso-crenatis ; vittd laterali nitide argented. 
D, 5—1/8 + A. t/17> ©. 175 P. 12; V. 1/5: 
D. 519 Ae 11S; &o— 
D. 6--1/10; A. 1/19; &c.— 
Lone. une. 2. lin. 6. 
