432 PROCEEDINGS OF THE ACADEMY OF [May, 



having the dark spots of the back quite large, rather sparse and con- 

 spicuous, even below the 1. 1. and to the caudal base. They also have 

 less ruddy on the under surface of the body. Nos. 37,871 to 37,875, 

 A. N. S. P., paratypes, with same data as type. 



The true generic position of this species would appear somewhat 

 doubtful, if the diagnosis of Pygopristis Miiller and Troschel is allowed 

 on its most important character, and that the absence of palatine 

 teeth. None of my large examples have any palatine teeth, and in 

 the 2 small ones there is only a single simple small conic cusp on each 

 palatine bone, except in one instance where 2. Thus P. serridatas 

 Valenciennes 4 may be found identical, though that writer does not 

 mention any dark blotches on the side of the body, and yet he does 

 say there are some traces of the dark shoulder-spot. 



Serrasalmus caribe Valenciennes 5 differs in the D. 20, A. 27, and no 

 scapular spot is mentioned or represented on the figure. It may also 

 be noted that Serrasalmo albus Humboldt and Valenciennes 6 is evi- 

 dently an older name for S. caribe, and should therefore replace it. 

 Serrasalmus rhombeus (Linnaeus) differs according to Miiller and 

 Troschel's figure 7 in having more palatine teeth. 



S. marginatus (Valenciennes) differs in the lower anal edge being- 

 black only, but not the hind caudal edge. Both»S'. spilopleura (Kner) 

 and S. gymnogenys (Giinther) are said to have 95 scales. S. elongatus 

 (Kner) differs in its elongated contour, the depth 2f. S. gibbus Cas- 

 telnau apparently has no spots whatever on the trunk. S. brandtii 

 (Liitken) has the scales 90, and the coloration is largely uniform or 

 with minute blackish dots. 



Among the species I have examined, S. humeralis Valenciennes, 

 S. maculatus Kner, S. ce'sopus Cope, S. iridopsis Cope and S. unimacu- 

 latus Cope, all were found to have more palatine teeth in each series, 

 besides various other characters. 



S. paraensis (Steindachner) I have not seen, and also have not been 

 able to consult its original description. 



(ATfJzxos-j berry-red; y(vstov } cheek; with reference to the ruddy cheek.) 



GASTEROPELECIN.E. 

 Chaloinus elongatus Giinther. 



Head 4 to 4f; depth 3£ to 3f; D. ii, 9, i; A. iii, 25, i to iii, 28, i; 

 scales in 1. 1. 38 to 40 + 4 or 5; 7 scales above 1. 1. ; 3 scales below 1. 1. 



* Hist. Nat. Puiss., XXII, 1849, p. 224. 



* L. c, p. 208. 



* Obs. z. Comp., II, 1835, p. 173, PI. 47, fig. 1. Orinoco R. 

 7 Hot. Ick., I, 1845, PI. 2, fig. 4. 



