284 FISHES OF WESTERN SOUTH AMERICA 
It is not without interest to make a comparison of the three genera superficially 
and to discover the extent to which Hoplerythrinus is actually intermediate to the 
other two. Table VI is taken from a study of the specimens referred to above. 
Similarity in form is shown by ordinary type, dissimilarity to the other genera 
in a given character shown by boldface, intermediates shown by italics. 
If this analysis is correct it seems to show that Hoplerythrinus is decidedly inter- 
mediate to the other two genera. 
In four of the characters named the intermediate nature of Hoplerythrinus is 
measurable; in none of them does it seem to occupy an extreme position; in four 
characters it resembles Hoplias more; in three the resemblance to Hrythrinus is 
greater. 
Hoplias is in the extreme position three times, in the intermediate position 
notatall. Hrythrinus is an extreme five times, an intermediate only once. 
Seventh Division—H emiodontine Group of Subfamilies 
Subfamily: HEMIODONTINAE 
Family Hemiodontidae Regan, 1911, Ann. Mag. Nat. Hist., (8), VIII, 13. 
Genus 150: HEMIODUS Miller 
Hemiodus Miller, 1842, Monatsch. Akad. Wiss. Berlin, 324; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 423; 
our 
Eigenmann, 1912, Mem. Carnegie Mus., V, 275. 
Type: Hemiodus crenidens Miller = Salmo unimaculatus Bloch 
Rio Orinoco to Peruvian Amazon and Rio Sao Francisco 
Gill-membranes free from each other and from the isthmus; scales below the 
lateral line of similar size to those above, and mostly small; dorsal fin shorter than 
the head; teeth in the upper Jaw only, pluricuspid, in a horseshoe-shaped series; 
fontanels large. 
372. HeEMIODUS MICROLEPIS Kner 
Hemiodus microlepis Kner, 1859, Denksch. Kk. Akad. Wiss. Wien, XVII, 155, pl. iv, fig. 8, Matto 
Grosso and Rio Negro; 
Cope, 1871 (1872), Proc. Acad. Nat. Sci. Phila., X XIII, 291, upper or mid-Amazon, Perkins 
collection, Philadelphia Academy Museum; 
Cope, 1878, Proc. Amer. Phil. Soc., 686, Maranon, Orton collection; 
Fowler, 1939 (1940), Proc. Acad. Nat. Sci. Phila., XCI, 257, two, 220 and 228 mm., Conta- 
mana. 
Hemiodus (Hemiodopsis) microlepis Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIII, 318. 
Upper and middle Amazons to Matto Grosso 
Genus 151: PTEROHEMIODUS Fowler 
Pterohemiodus Fowler, 1939 (1940), Proc. Acad. Nat. Sei. Phila., XCI, 257. 
