ANNOTATED LIST OF THE SPECIES 119 
form, none on vomer or palatine; eye small and lateral, covered; adipose very short; 
dorsal short; pectoral with stout, doubly serrate spine; anterior rays of anal en- 
larged as intromittent organ in male. 
66. TRACHYCORYSTES GALEATUS (Linnaeus) 
Plate V, fig. 1 
Silurus galeatus Linnaeus, 1766, Syst. Nat. ed. xii, 503, based on Seba, Locupl. Rer. Nat., III, pl. 
Oddie ake, 7/6 
Bloch, 1795, Ausl. Fische, VIII, 39, pl. 369, fig. 1; 
Bloch and Schneider, 1801, Syst. Ichth., 384. 
Pimelodus galeatus Lacépéde, 1803, Hist. Nat. Poiss., V, 97, and 114. 
Auchenipterus galeatus Giinther, 1864, Cat. Fish. Brit. Mus., V, 196. 
Trachycorystes galeatus Eigenmann and Higenmann, 1888, Proc. Cal. Acad. Sci., (2), 1, 155; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 279; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 396; 
Eigenmann, 1912, Mem. Carnegie Mus., V, 198. 
Auchenipterus striatulus Steindachner, 1876, Siisswf. sudést. Brasil, IIT, 98. 
Trachycorystes striatulus Eigenmann and Kigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 155; 
Von Ihring, 1937, Copeia, no. 4, 201. 
The Orinoco, Peru to Rio Sao Francisco 
15794, 8, 114-188 mm., Iquitos, Allen, September, 1920. 
15795, 1, 55 mm., brook near Rio Itaya, Iquitos, Allen, September, 1920. 
15796, 2, 100 and 113 mm., creek, Yurimaguas, Allen, November, 1920. 
15975, 1, 157 mm., Iquitos, Morris, 1922. 
Von Ihring, 1937, eliminates the boundary between the species 7’. galeatus and 
striatulus, adhering to the latter name, created by Steindachner, in place of the older 
Linnean name. In this matter he appears to be guided by the opinion of Starks, 
1906, who recognizes no distinction but the differences in the rugosity of the skin 
of the head, and finds all degrees of rugosity. 
Other differences seem to exist, such as finray counts. Our specimens appear 
very close to the Linnean galeatus. 
Our Iquitos specimens may be characterized as follows: stout, bulldog-like, 
all contours rounded and swollen except the fin insertions; Jaws subequal, mandible 
slightly and roundly projected. Dorsal contour of head nearly straight, back rather 
straight and strongly notched at fin insertions; ventral contour moderately and 
uniformly convex; caudal peduncle short and elevated, at its lowest point 1.2 in the 
interorbital space. 
Nares widely spaced, in a rectangle, their valves minute flaps; eye moderate, 
5.3 in head, 3.2 in the interorbital; bones of head thickened and finely granular, 
including the coalesced occipital processes and dorsal plate, to which the dorsal 
spine is broadly articulated by a ball-and-socket joint. First mental barbel short, 
half the interorbital space, reaching to base of second mental; the latter longer, 
reaching to end of pectoral base; maxillary barbel reaching past middle of pectoral 
spine, lying in a groove which subtends the orbit and opercle to near the extremity 
