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Show 240 MR. R. COLLETT ON HYBRID GROUSE. [Ap also leaves and twigs of different plants, procured principally on the marshes, and occasionally (like Arctostaphylos alpina) from the true alpine district; likewise from various berries, and occasionally from birch-catkins. Several of these articles of nourishment form the food of Blackgame ; nevertheless it is certain that most of them come from marshy places, from which it must be assumed that its diet most resembles that of the Willow-Grouse. Skeleton. In a skeleton of a male from Saltdalen (Nordland) the measurements are as follows :- millim. Length of the skull (bill included) 63 Greatest breadth of the skull 28 Length of scapula 78 Length of humerus 73 Length of radius 65 Length of ulna 71 Length of os coracoideum 55 Length of metacarpus n 39 Length of the two phalanges of digitus n 31 Length of furcula (to the edge of the plate).... 66 Length of sternum 120 Greatest height of crista sterni 34 Length of pelvis (to the first caudal vertebra) . . 73 Greatest breadth of pelvis (across ossa ischii).... 57 Length of femur 76 Length of tibia 21 Length of tarsus 45 Length of middle toe (claw not included) 45 As the skeletons of the two parents, Lagopus albus and Tetrao tetrix, resemble each other so nearly that, apart from their difference cf size, it would be difficult to find out the most trifling characteristic, this hybrid hardly has one distinctive feature in the structure of its skeleton beyond its difference in size. Christiania, March 1886. EXPLANATION OF THE PLATES. PLATE XXI. Hybrid between Lagopus albus and Tetrao tetrix. Fig. 1. Male in winter dress. Fig. 2. Female in winter dress. PLATE XXII. Hybrid between Lagopus albus and Tetrao tetrix. Fig. 1. Young male in early autumn dress. Fig. 2. Young male in late autumn dress. |