52 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
and Festa, Boll. Mus. Zool., etc., xv, no. 362, 1899, 27 (Vinces and Foreste 
del Rio Peripa, w. Ecuadér); no. 399, 7 (Laguna de] Pita, Panam4).—THavER 
and Banes, Bull. Mus. Comp. Zool., xlvi, 1906, 216 (Sabana de Panamé). 
[Thamnophilus] atrinucha SHarpr, Hand-list, iii, 1901, 14. 
[Thamnophilus] nevius atrinucha Hevtmayr, Abh. K. B. Akad. Wiss., ii. KI, 
xxii Bd., iii. Abth., 1905, 659 (crit.). 
Thamnophilus nevius atrinucha CARRIKER, Ann. Carnegie Mus., vi, 1910, 602 
(Caribbean lowlands and foothills, Costa Rica; crit.; habits; descr. nest and 
eggs). 
ERIONOTUS PUNCTATUS GORGONZ (Thayer and Bangs). 
GORGONA ISLAND ANTSHRIKE. 
Similar to EZ. p. atrinucha but adult male with forehead more 
extensively grayish,” the adult female with lateral under parts paler 
(nearly concolor with median portion). 
Gorgona Island, Bay of Panama. 
Adult male.—Length (skins), 148-148 (146); wing, 70-75 (72.1); 
tail, 57-61 (59); culmen, 18.5-20 (19.4); tarsus, 20-21 (20.5); middle 
toe, 12.5-13 (12.7). 
Adult female——Length (skins), 140-148 (144); wing, 68.5-72.5 
(70.1); tail, 54.5-57.5 (56.1); culmen, 18.5-20 (19.1); tarsus, 21-21.5 
(21.1); middle toe, 13-14 (13.4)? 
Thamnophilus gorgone THAYER and Banes, Bull. Mus. Comp. Zool., xlvi, no. 5, 
June, 1905, 95 (Gorgona Island, Bay of Panamé; coll. E. A. and O. Bangs). 
Genus DYSITHAMNUS Cabanis. 
Dysithamnus ¢ CaBanis, in Wiegmann’s Archiv fiir Naturg., xili, pt. i, 1847, 223. 
(Type, Lanius guttulatus Lichtenstein.) 
Dasythamnus (emendation) BurMEISTER, Syst. Ueb. Th. Bras., iii, 1856, 82. 
Silvestrius € Bertoni, Aves Nuevas del Paraguay, 1901, 136. (Type, Thamno- 
philus (Silvestrius) flavescens Bertoni= Myothera mentalis Temminck.) 
Small Formicariide (length about 100-115 mm.) with bill much 
shorter than head, tail less than three-fourths as long as wing and 
slightly rounded, tarsus one-third as long as wing, and plainly colored 
plumage (olive or olive-greenish above, becoming gray or slate colored 
on head and neck, the pileum sometimes streaked or spotted with 
blackish, mostly whitish or yellowish below, sometimes with streaks 
on throat and chest, females more brownish, with pileum rufescent. 
Bill much shorter than head, its width at frontal antiz slightly 
greater than its depth at same point and equal to about half the dis- 
tance from nostril to tip of maxilla; culmen distinctly but not 
sharply ridged, nearly straight for most of its length, strongly and 
rather abruptly decurved terminally, the tip of maxilla moderately 
@ On comparison with a large series of E. p. atrinucha I find that most of the char- 
acters mentioned by Mr. Bangs do not hold. 
b Four specimens. 
cdbw, hineinbegeben; Odyvoc, Gebiisch. (Cabanis.) 
@ Named for Dr. Felipe Silvestri. 
