. TETEAGONOPS. : 55I 



duller bird, inasmuch as it lacks the shining black long nuchal crest shown in the 

 original figure of the type and in all dissected male birds. 



This difference in the sexes is also shown in Tetragonops rhamphastinus, but is not 

 Noticed by Captain Shelley in his catalogue ; and though mentioned in Marshall's 

 monograph in the case oi.T.frantzii is not alluded to in the case of the allied form. 



All the specimens of this bird we have seen came from Costa Rica, except one, and 

 this was sent by Arce from Veraguas after the second paper on his birds was published 

 in 1870. 



ram. RHAMPHASTID-ffi], 



The Family Ehamphastidse is restricted to the Neotropical region, and is found 

 almost universally over the heavily forested districts from Southern Mexico to the 

 confines of Argentina, some forms being restricted to the upland woods of the higher 

 mountains, others to the vast forests of the lowlands. 



Of the five genera into which the family is divided, four occur within our limits^ 

 Andigena alone being absent. Mhamphastos is represented by three species out of a 

 total of fourteen, Pteroglossus by three out of eighteen, 8elenidera by one out of seven, 

 and Aulacorhamphus by three out of fourteen. We thus have ten species out of a 

 total of fifty-nine known forms, and our region is fairly stocked with members of this 

 singular family ; but far larger numbers are found in South America, the metropolis 

 of the Rhampihastidse being the upper waters of the great Amazons basin and the 

 eastern slopes of the Andes from Colombia to Bolivia. 



The enormous size of the bill in the Rhamphastidse at once renders these birds 

 easily recognizable. This organ is of curious structure, very light, but strongly built 

 within by a bony network. The tongue is also very peculiar, being long, narrow, and 

 thin, and deeply lacerated towards the end. The tail-feathers, as in the Capitonidse, 

 are ten in number, the oil-gland is tufted, and there are no caeca. The Rhamphastidae 

 further differ from the Capitonidse in the form of the vomer, which, instead of being 

 bifurcated at its distal end, is truncated and has a rounded extremity. 



In the general structure of the body the Toucans closely resemble the Capitos and 

 Woodpeckers — so much so, that, apart from the cranial characters, slight grounds of 

 separation exist, a point strongly insisted upon by Garrod and Forbes. 



The Rhamphastidse attracted Gould's attention early in his career, and he produced 

 two large illustrated monographs of the family. A small edition, also illustrated, was 

 brought out by J. H. C. F. and J. W. Sturm in 1841, and the ' Catalogue of Birds 

 in the British Museum,' vol. xix., contains a complete synopsis of the family by 

 Mr. P. L. Sclater. The latter book contains lists of all the specimens gathered 

 by us for this work, and has been of great use to us in our account of the species 

 here treated of. 



