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Show 128 MR. o. SALVIN O N BIRDS F R O M [Feb. 4, I may add that in a Bat (Pteropus medius) I found the superior oblique to have a relation like that in the Lemur to the superior rectus, but the inferior oblique was close up to the corneal limit. It may be also proper to state that these variations in the muscular attachments do not appear to depend in any definite manner on alterations in the position of the orbit. M. Broca, in the • Revue d'Anthropologie,' 1877, p. 356, gives a table of the obliquity of the orbit in members of the Quadrumana, this obliquity being determined by measuring the angle between the base-line of the skull (in his series the base-line chosen is the plane of the foramen magnum) and the axis of the orbit. This axis is a line passing outwards and forwards from the optic foramen through the centre of the orbital aperture. From this direction of the axis it will be seen (a) that it does not correspond with the visual axis, (6) that its obliquity is made up of an obliquity to the median plane of the head and of an obliquity to the horizontal base-line of the skull. As instances of the great varieties found in this angle, he gives the mean angle in Orang as 45°*62, Cercopithecus 28°*43, Cebus 22°*3, Mycetes 67°-17, Lemurs 41°*05. It seems possible that a comparison of the angles between the two visual axes when the eyes are at rest, would be more likely to afford some explanation of the meaning of the gradual change in the relative position of the eye-muscles ; and the direction of these axes it appears at present to be impossible accurately to ascertain. 5. O n some Birds transmitted from the Samoan Islands by the Rev. T. Powell. By O S B E R T SALVIN, M.A., F.R.S. [Received January 6, 1879.] The collection, which contained specimens of the following five species of birds, was placed in my hands by Mr. Sclater, because there were two Petrels amongst them, a family of birds to which I have lately paid considerable attention. The skins were obtained by the Rev. Thomas Powell, of Faleatili, Upolu, Samoan Islands, during a visit to the islands of Tutuila and Manoa, the two easternmost islands of the group, and transmittted to Mr. Sclater, with a request that he would have them named. This I have endeavoured to do, but have only succeeded in finding names for three of the five species, the other two being apparently undescribed : - 1. PlNAROLESTES POWELLI, Sp. nov. Saturate brunneus, alls et cauda nigricantioribus; abdomine rufescenti-brunneo; rectricibus tribus utrinque extimis terminalis ; rostro et pedibus plumbeo-corneis. Long. tot. alee 31, caudee 32, tarsi 0 9, rostri a rictu 1*1. Hab. Tutuila, Samoan Islands (T. Powell). Obs. Sp. P. vitiensi affinis, sed major, alis et cauda saturatius brunneis;. |