FISH. 



137 



Colour.— Not noticed in the recent state. In spirits, it appears silvery, with the back and upper 

 part of the sides deep dusky blue, the two colours separated by a well-defined line. 



Habitat, Jquique, Peru. 



This is probably an undescribed species of Engraulis ; nor am I aware that 

 authors have hitherto noticed any from the west coast of America. Mr. Darwin 

 obtained two specimens which are precisely similar to each other. The species 

 closely resembles the common European Anchovy,* differing principally in its 

 larger head, and more backward ventrals in respect to the dorsal. 



Family.— PLEURONECTID^. 



Mr. Darwin's collection contains individuals of five species belonging to this 

 family, besides the drawing of a sixth ; but the specimens brought home are dry, 

 and badly preserved. Two appear to have been previously noticed ; but it is 

 difficult to pronounce upon the other three with certainty, neither do they admit 

 of being very accurately described. These last, therefore, I shall not venture to 

 name, but merely point out a few of their principal characters, adding the 

 localities whence they were obtained. 



The species, of which there is a drawing, I conceive to be certainly new ; and 

 as its characters are very distinguishable, I shall name it in honour of the gen- 

 tleman, one of the officers of the Beagle, by whom the drawing was made. 



1. Platessa Orbignyana. Vol.? 



Platcssa Orbignyana, Vol. in D'Orb. Voy. dans l'Amer. Merid. Atl. Iclith. PI. 16'. fig. 1. 



Form. — Oval ; greatest breadth two and a half times in the length. Eyes on the left side, near 

 together, and equally in advance. Teeth in a single row, sharp-pointed, moderately strong, 

 rather widely separate : posterior extremity of the maxillary cut nearly square. Dorsal com- 

 mencing in a line with the eyes, and leaving a space between it and the caudal. The lateral 

 line takes a sweep over the pectoral. Upper or eye side of the body slightly rough, with the 

 scales finely ciliated; under side smooth, the scales on this side not ciliated. 



Colour. — " Above dirty reddish brown ; beneath faint blue : iris yellow." — D. 



Length 8 inches 9 lines. 



Habitat, Bahia Blanca, where it is said to be plentiful. 



This species agrees so well with the figure of the P. Orbignyana in DOr- 

 bigny's Voyage, that I have little hesitation in considering it the same, — but as 



* I am indebted to Mr. Yarrell for the loan of a specimen of our common Anchovy for comparison. 



T 



