Mr. J. Gould on a new species of Prion. 57 



of Prion, captured on the island of Madeira, or on the neighbouring 

 rocky islets called the Desertas. I also exhibit five other species 

 (forming part of my own collection), which I consider to belong to 

 the same beautiful group, and which were captured by myself during 

 my voyages to or from Australia. 



The entire iSeries present a great similarity in the colour of their 

 plumage, l)uta great diversity in the breadth or lateral development of 

 their mandibles, as well as in the fringe-like pectinations of the base of 

 the upper mandible; this latter character being much more prominent 

 in the larger than in the smaller species of the group, in which, 

 indeed, it is almost obsolete, if not entirely absent. I consider the 

 members of this genus to constitute a very distinct group among th( 

 Petrels, quite equal in point of interest and value to that of th« 

 Thalassidromce. I have had many opjiortunities of observing tht 

 whole of them in their oceanic haunts, and did not fail to observe that 

 every tive or six degrees of latitude was frequented by a different and 

 distinct species : they all inhabit the wide ocean, and rarely visit the 

 land except for the purpose of incubation : they are often seen in 

 immense flocks, and sometimes in multitudes : they never mount 

 high in the air, but are altogether the most light, buoyant and fairy- 

 like members of the great group to which they belong : their great 

 stronghold is the temperate latitudes of the southern ocean, and 

 until the occurrence of the present new species, I have never heard 

 of one being found north of the equator. The species to which the 

 Madeiran bird is most nearly allied, is that to which I have given 

 the name of P. Ariel, and which I met with and shot in great 

 numbers in Bass's Straits, It differs, however, in being smaller in 

 all its admeasurements, in having a shorter, more swollen or robust 

 bill, particularly with reference to the nostrils and the terminal hook 

 of the upper mandible. For this new' species I propose the name of 



Prion brevirostris. 



Upper surface delicate blue ; edge of the shoulder, the scapularies, 

 outer margins of the external primaries and the tips of the middle 

 tail-feathers black ; lores, sides of the head and all the under surface 

 white, stained with blue on the flanks and under tail-coverts; bill 

 light blue, deepening into black on the sides of the nostrils and at 

 the tip, and with a black line along the side of the under mandible ; 

 feet light blue, the interdigital membrane flesh-colour. 



Total length, 10|^ inches; bill, -Lf ; wing, 6|- ; tail, 3| ; tarsi, 1:^. 



Descriptions of some new Species of Ant-Thrushes 



(FORMICARIIN.4;) FROM SaNTA Fe DI BoGOTA. 



By Philip Lutley Sclater, M.A., F.Z.S. 



1. GrALLARIA HYPOLEUCA. 



G. supra ferrvfjinea, loris alhiiiis : subtuti alba, lateribus tnagis 



cinerascentibus : tibiis et hijpochondriis brunnescentibus. 

 Long, tota 6".'), alse 3 '5, caudae 1'8. 

 The collection of the Jardin des Plantes at Paris contains the only 



