PLATYRHYNCHUS.—RHYNCHOCYCLUS. 7 
Supra olivescenti-olivaceus ; alis et cauda fuscis umbrino limbatis ; vertice medio castaneo utrinque nigro margi- 
nato; loris, superciliis, ciliis ipsis, tectricibus auricularibus et corpore subtus flavidis ; stria postoculari et 
altera infra oculos nigris ; hypochondriis sordide olivaceis: rostri maxilla nigra, mandibula sordide alba, 
apice albida ; pedibus pallide corylinis. Long. tota 3°4, ale 2°15, caude 0-8, rostri a rictu 0°5, tarsi 0-5. 
(Deser. maris ex Santa Fé, Panama. Mus. nostr.) 
© mari similis, 
Hab. Costa Rica, VWalza (Carmiol+); Panama, Bugaba®, Volcan de Chiriqui, Santa 
Fé5 (Arcé), Lion Hill (If Leannan 12 ?).—Gutana’. 
This, the smallest of the three species of Platyrhynchus found within our region, 
appears to be not uncommon in the State of Panama and in Costa Rica, as specimens 
have been included in most of the large collections made in those districts. We find, 
however, no accounts of its habits, though doubtless, like its congeners, it frequents 
the underwood of the denser forests. Mr. H. Whitely met with the same species at 
Bartica Grove in British Guiana’; it occurs also at Albina in Surinam. It has not 
yet been noticed elsewhere in South America, though we expect it to be found in 
suitable places in the country intervening between Guiana and Panama. 
The only southern species at all closely resembling P. superciliaris is P. coronatus 
of the Upper Amazons valley. But the latter is a larger, darker bird, with a less 
clearly-defined yellow under surface. 
RHYNCHOCYCLUS. 
Cyclorhynchus, Sundevall, K. Vet. Ak. Handl. 1835, p. 83 (nec Kaup, 1829) (type Platyrhynchus 
olivaceus). 
Rhynchocyclus, Cab. & Heine, Mus. Hein. ii. p. 56 (1859) ; Scl. Cat. Birds Brit. Mus. xiv. p. 165. 
Twelve species are included in Rhynchocyclus as a whole, all of them belonging to 
the Neotropical Region, the range of the genus extending from Southern Mexico to 
South Brazil. All the members are forest birds, as are the species of Platyrhynchus. 
This genus seems to us to be quite out of place in Mr. Sclater’s arrangement, where 
it stands in the “ Elaineine ” next Mytozetetes. 
The bill of R. brevirostris is constructed almost exactly like that of Platyrhynchus, 
the nostrils are similarly shaped and placed in the same position, and the rictal bristles 
are equally developed. The tarsi are comparatively shorter and the tail much longer. 
The secondaries are longer in proportion to the primaries, and the members of the 
genus generally of larger size, and of olivaceous rather than brown tints. 
Rhynchocyclus is divisible into four sections, only two of which occur in our region. 
In one of these sections (2. brevirostris and its allies) the male is distinguished by the 
peculiar structure of the outer web of the outermost quill, the barbs of which are 
slightly recurved and pointed so as to form a stiff pectinated edge, much as in the 
genera Stelgidopteryx, Oxyrhamphus, &c. 
The section containing R. sulphurescens and its allies has not this peculiarity. 
