FISH. 161 



falling to the middle before losing itself in the caudal. Scales small, covering the whole head 

 and body, except the snout in front of the eyes, the jaws, and the limb of the preopercle. The 

 free portion of each scale marked with several small concentric circles, the free edge finely 

 ciliated : the basal portion with a fan of seven striae, and the spaces between these deeper striae 

 with minuter striae running transversely: the basal margin cut square. 



Pectorals attached rather low down, and a little posterior to the terminating angle of the 

 opercle ; their length about three-fourths that of the head : the fourth to the eighth rays 

 longest ; the first ray only half the length of the second ; the first two, and the last three or 

 four, simple ; the rest branched. Ventrals about four-fifths the length of the pectorals, and in 

 advance of those fins by nearly half their own length ; their spine very distinct. First dorsal 

 short, commencing immediately above the insertion of the pectoral : all the spines very slender, 

 with the intervening membrane delicate ; the second longest, equalling about half the depth ; 

 the third and following ones gradually decreasing. Second dorsal long, separated from the 

 first by a very small interval, and occupying a space just equal to the distance between its com- 

 mencement and the end of the snout: the rays gradually decreasing in length from the anterior 

 ones, which equal three-fourths of the depth ; all simple, or if branched, only so at their 

 extreme tips. The interval between the second dorsal and the caudal contained eight-and-a- 

 half times in the entire length. Anal commencing under the sixth ray of the second dorsal, 

 or exactly at the middle point of the entire length, caudal excluded ; extending a trifle beyond 

 the second dorsal, but in other respects answering to that fin. Caudal square when spread, 

 but very slightly notched when the rays are close ; contained six-and-a half times in the entire 

 length ; the principal rays branched. 

 Colour. — (,7ra spirits.) Back and upper half of the sides pale olivaceous, with about seven or eight 

 abbreviated, transverse, dusky fasciae ; beneath these are two irregular lines undulating longi- 

 tudinally in a zig-zag manner, and having rather a tendency to meet at the angles, so as to 

 form a connected longitudinal chain of diamond-shaped links. Lower portion of the sides 

 and abdomen silvery. Tubal pores of the lateral line white, making this line very evident. 

 Dorsal and caudal fins speckled with small dusky spots and points. Pectorals, ventrals, and 

 anal, quite plain, and whitish. 



A second specimen in the collection exactly resembles the above, except in being not quite 

 so large, and in having a ray less in each of the two dorsal fins. 



Habitat, Chonos Archipelago, W. coast of S. America. 



The genus Aphritis was first established by M. Valenciennes, in the appendix 

 to the eighth volume of the " Histoire des Poissons," for the reception of a small 

 Percoid fish obtained by MM. Quoy and Gaimard in Van Dieman's Land, in- 

 habiting fresh-water. The species above described, which was taken by Mr. 

 Darwin in Lowe's Harbour, South of Chiloe, appears to be referable to the same 

 genus. It differs, however, in many respects from the A. Urvillii, the only one 

 which Valenciennes has noticed. The relative situation of the first dorsal with 

 respect to the pectorals, and of the anal with respect to the second dorsal, is dif- 

 ferent : there are fewer rays in the anal, and more in the second dorsal : the 

 upper, instead of the lower jaw, as represented in Valenciennes's figure, is 



Y 



