Olivaceous Elaenia

Here the details of the Olivaceous Elaenia named bird below:

SCI Name:  Elaenia mesoleuca
Protonym:  [Muscicapa] mesoleuca Preis-Verzeichn.Saugeth.Vog.Mex.gesam. p.2
Taxonomy:  Passeriformes / Tyrannidae / Elaenia
Taxonomy Code:  oliela1
Type Locality:  Mexico; type is labeled Montevideo, Uruguay, fide van Rossem, 1934, Trans. San Diego Soc. Nat. Hist., 7, p. 350.
Author:  Deppe
Publish Year:  1830
IUCN Status:  Least Concern

DEFINITIONS

ELAENIA
(Tyrannidae; Ϯ Yellow-bellied Elaenia E. flavogaster) Gr. ελαινεος elaineos  of olive-oil, oleaginous  < ελαια elaia  olive; "Elænia n. g. ⁶)  Musc. pagana Licht.; brevirostris, — modesta, — aurifrons Pr. Max; — Hylophilus cinerascens ejusd.  Numerosæ americanæ, transitum ad Tyrannides præbentes; Fringillis subsimiles.   ...    ⁶) Rostrum crassiusculum, breve, basi dilatatum, altitudine latius; carina dorsali subacuta, sutura recta.  Membrana narium plumulis tecta.  Vibrissæ tenues.  Alæ mediocres vel sub-breves, rotundatæ, remigib. 3-5 reliqvis longioribus.  Pedes mediocres, digitis brevibus, subliberis.  Olivaceæ-cinerascentes; sæpe subtus, interdum vertice flavæ. — Eλαινιος, oleagineus." (Sundevall 1836); "Elaenia Sundevall, 1836, Vetensk. Akad. Handl., 1835, p. 89. Type, by subsequent designation (Gray, 1855, Cat. Gen. Subgen. Birds, p. 49), Muscicapa pagana Lichtenstein = Pipra flavogaster Thunberg." (Traylor in Peters, 1979, VIII, pp. 26-27).  
Var. Elaenea, Elainea, Elainia, Eloenia, Elana, Elania.

mesoleuca / mesoleucus
Gr. μεσολευκος mesoleukos  middling-white, streaked white, black gemstone with a white stripe  < μεσος mesos  half, middle; λευκος leukos  white.