116 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



at Maldonado, in a lake that had been suddenly drained. There are three spe- 

 cimens in the collection, none of them exceeding the length above given. Mr. 

 Darwin, however, states in his notes, that he believes them to be full grown, 

 having taken them so repeatedly, in brooks, of the same size. The number of 

 spots varies from nine to twelve, and is sometimes different on the two sides of the 

 same specimen. 



Independently of the spots, which at once characterize this species, it is 

 readily distinguished from the last by its teeth, which are more cutting than point- 

 ed, and in this respect rather departing from the character of the genus as esta- 

 blished by Valenciennes. 



1. Lebias lineata. Jen. 



Plate XXII. Fig. 2. 

 L. corpore subelongato, subcompresso, viridescenti-fusco ; lateribus lineis circiter 

 seplem longitudinalibus nigris, e maculis parvis subconfluentibus formatis : dentibus 

 uniseriatis : caudali rotimdatd. 



D. 9 ; A. 9; C. 26, brevibus inclusis ; P. 13; V. 6. 

 Long. unc. 1. lin. 10. 

 Form.— General form very similar to that of the Pcetilia decem-maculata. Slightly compressed ; the 

 depth one-fifth of the length ; the length of the head about four-and-a-half times in the 

 same. Head depressed: snout obtuse : mouth small; the commissure horizontal. Upper jaw 

 very protractile ; the lower one rather the longest, when the mouth is shut. Teeth forming 

 a single closely-set series, somewhat compressed at bottom, the cutting edges tricuspid. 

 Diameter of the eye nearly one-fourth the length of the head. Some large conspicuous pores 

 on the lower jaw, passing upwards in a series along the margin of the preopercle, not very 

 near together, about eight or nine in all. 



Scales large, covering the head and all the pieces of the gill cover, as well as the body. 

 About eight in the depth, and thirty in a longitudinal line from the gill to the caudal. 

 One taken from the middle of the side of a semi-elliptic somewhat oblong form ; the free 

 portion very finely striated, the basal with ten or twelve deeper-cut striee, these last nearly 

 parallel, and of equal lengths. Lateral line faintly marked out by a dotted line ; the first 

 half in the third row of scales from the top, the last half in the fourth row. 



Dorsal commencing at exactly the middle point of the entire length. Anal opposite and 

 similar. Caudal rounded. Pectorals small, about two- thirds the length of the head. Ventrals 

 smaller, barely one-half of the same. The pectorals, when laid back, reach to the insertion of 

 the ventrals ; but the latter hardly attain to the anal. 

 Colour.— Greenish-brown, with six or seven longitudinal dark lines on the sides, the lines appa- 

 rently made up of spots for the most part confluent, but here and there not so, interrupting the 

 continuity of the lines. All the fins pale dusky, without any spots or markings. 

 Habitat, Maldonado. 

 This new species of Lebias was taken by Mr. Darwin in the same lake at 



