PISHES. 233 



their exterior margin is long and acute, though shorter than any of their soft rays, which 

 bifurcate thrice, save the i^osterior one, which divides but twice, and the anterior only once. 

 Their external margin is broad and rounded. The pectorals are a little longer than the ven- 

 trals, broad exteriorly when ex^Danded, and composed of soft and slender rays, which bifurcate 

 but twice upon their length. 



Br. VII; D XI. 10+1; A III. 10; C 4. I. 8. 7. I. 3; YI. 5; P 16. 



The scales are well developed, minutely serrated upon their posterior margin, which is con- 

 vex or rounded. Their anterior margin is subtruncated, whilst their upper and lower margins 

 are almost rectilinear. Eight distinct rows may be counted between the anterior margin of the 

 first dorsal and the lateral line, and from twenty-two to twenty-five beneath it and the ventral 

 line. They diminish considerably in size upon the sides and belly, becoming very minute 

 under the throat. The upper surface of the head and the cheeks, the suborbitals and maxillary 

 are covered with them, smaller, however, on the cephalic region proper than on the cheeks, and 

 quite minute on the maxillary. Those covering the opercular apparatus are again large and 

 conspicuous, being nearly as large as those of the trunk. The lateral line is very conspicuous ; 

 there are in it from sixty-eight to seventy scales. Prom the upper part of the opercular appa- 

 ratus it constitutes a gradually raised curve to nearly opposite the posterior portion of spiny 

 dorsal; hence the ^urve is continued, gradually descending to nearly opposite the posterior 

 margin of the soft dorsal by a series of undulations ; then runs almost straightway to the base 

 of caudal, along the middle of the peduncle of the tail. 



The coloration is of a golden yellow; the upper part of the flanks and dorsal region being 

 brownish or blackish owing to the presence of diffused spots and maculee. The fins are uni- 

 color, greyish yellow. The inferior surface of the head is whitish. 



This fish is said to inhabit most of the rivers of the republic of Chile. The specimen figured, 

 together with several others, was caught in a tributary of the Eio de Maypu, near Santiago. 



Plate XXIX, fig. 1, represents, size of life, Fercichthys chilensis, seen in profile, 

 fig. 2, is a scale of the dorsal region, 

 fig. 3, a scale from the lateral line, 

 fig. 4, a scale of the abdominal region. 



Figs. 2, 3, and 4 are magnified. 



FERCICHTHYS MEL ANOP S , Giravd. 



Plate XXX, Figs. 1—5. 



Spec. char. Mouth of moderate size, posterior extremity of upper maxillary reaching the ver- 

 tical of the anterior rim of orbit. Palatine teeth occupying but a small area towards the an- 

 terior extremity of these bones. Opercular spine not very conspicuous. Branchiostegals, six. 

 G-round-color whitish, minutely and densely dotted with black ; dots crowding upon the middle 

 of the scales under the shape of a central blotch, giving to the whole fish quite a dark hue. 



Syn. Fercichthys melanojps, GtRD. Proc. Acad. Nat. Sc. Philad. VII, 1854, 197. 



Dbscr. This species does not apparently attain a very large size, judging of it from the fact 

 that the specimen figured is the largest of the lot collected. It bears a general resemblance to 

 F. cMlensis above described, having the same general shape of the head and body; but the 

 peduncle of the tail being less developed, its aspect is rather more contracted. The greatest 

 depth of the body, which corresponds to the anterior margin of the first dorsal fin, is equal to 

 the length of head, and is contained about three times and three-fourths in the total length; 

 whilst the least depth, taken on the middle of the peduncle of the tail, enters in that same 

 30* 



