348 CHARACINID.S. 



The origin of the dorsal fin is a little nearer to the extremity of the 

 snout than to the root of the caudal, above the fifth or sixth anal 

 ray ; caudal deeply forked ; the ventral is inserted below the middle 

 of the pectoral, which extends nearly to the origin of the anal. Light 

 reddish olive with a silvery lateral band. 



Guatemala. 

 a-b. From 5 to 6 inches long. Chagres River. From the Collection 

 of Messrs. Salvin and Dow. 



c. Several young specim as. Huamuchal. F^m .Mr. Salvin's Col- 



lection. 



d. idult : skeleton. Chagres River. From the Collection of Messrs. 



Salvin and Dow. 

 The lengm of the abdominal portion of the vertebral column is 

 contained once and four-fifths in that of the caudal ; the first ver- 

 tebra is large, evidently composed of two confluent vertebrae. Ribs 

 well developed. The interhaemal spines do not correspond with the 

 haemals, the nine anterior interhaemals being attached to the haemal 

 of the first caudal vertebra. 



B. Mandibulary teeth in a double series : Cynopota*"*'*. 



6. Anacyrtus argenteus. 



Hydrocyon argenteus, Vol. in ef Orb. Voy. Am. Mh-id. Poiss. pi. 9. fig. 1. 

 Cynopotamus argenteus, Cuv. 8f Vol. xxii. p. 317. 



D. 12. A. 53. V. 8. L. lat. 120. 



Intermaxillary and mandibulary teeth in a double series: the 

 outer series of the intermaxillary is formed by very short conical 

 teeth, the inner by four canine teeth. Edge of the maxillary toothed. 

 The outer series of the mandible contains strong canines, the inner 

 being formed by very small teeth. Back elevated, the upper profile 

 of the head and nape forming an S-shaped curve. The height of the 

 body is one-third of the total length (without caudal), the length of 

 the head a little less than one-fourth. ( Vol.) 



Rio de la Plata 



7. Anacyrtus humeralis. 



Hydrocyon humeralis, Vol. in <f Orb. Voy. Am. MSrid. Poiss. pi. 1 1. fig. 2. 

 Cynopotanms humeralis, Cuv. 8f Val. xxii. p. 320. 



D. 11. A. 44. L. lat. 115. 



Dentition as in A. argenteus. Body oblong, its height being equal 

 to the length of the head, and two-sevenths of the total (without 

 caudal). The upper profile of the head is somewhat concave. A 

 more or less distinct blackish spot on the shoulder ; a blackish band 

 along the root of the caudal and along its middle rays. ( Val.) 



Buenos Ayres. 



Kner (Denkschr. Acad.Wiss. Wien, 1860, xviii. p. 49. taf. 7. fig. 15) 

 describes a Cynopotamus humeralis, which, however, appears to be 

 distinct, having only 78-95 scales in the lateral line and 45-48 

 anal rays. 



