OCR Text |
Show 224 MR. R. COLLETT ON HYBRID GROUSE. [Apr. 20, EXPLANATION OF PLATE XX. Fig. 1. Side view of jaws of Hybodus dubrisiensis, Mackie. pa, pterygo-quadrate ; mJc, Meckelian cartilage; p, pterygo-trabecular process; ot, otic process; km, hyomandibular; ch, cerato-hyal. (B.M. 41675.) 2. Under view of the same: tu, tuberosity on cerato-hyal. 2 a, natural transverse section of right cerato-hyal. 3. Teeth of the same, twice nat. size, a, anterior tooth; b, hinder tooth. 4. Hyomandibular of the same, back view, t, tuberosity. 5. Restoration of mandibular and hyoid arches of Hybodus dubrisiensis. 6. Section of the upper border of quadrate region of pterygo-quadrate of type specimen of Hybodus dubrisiensis, showing thickening. Figs. 1, 2, 4-0 are of the natural size. 4. On the Hybrid between Lagopus alhus and Tetrao tetrix, By ROBERT COLLETT, C.M.Z.S. [Eeceived April 1, 1886.] (Plates XXL, XXII.) Introduction, p. 224. Young plumage, p. 231. Distribution, p. 225. Sex, p. 232. Propagation in Norway, p. 226. Supposed parentage, p. 232. Diagnosis and Configuration, p. 227. j Other Hybrids of Lagopus, p. 236. Measurements of <$ & $ , p. 228. Habits, p. 238. Food, p. 239. Skeleton, p. 240. Colouring, p. 228. Winter plumage, p. 229. Summer plumage, p. 230. Introductory Remarks. The existence in Northern Europe of two kinds of natural hybrids amongst the Tetraonidae was already known in the last century, and one form of these is rather common in the forests of Norway and Sweden, as well as in some other parts of Europe, being met with annually in many districts, where its hybrid character is, as a rule, well known to the inhabitants. This is the " Rakkelf ugl," the cross between the male of Tetrao tetrix and the female of Tetrao urogallus. The male of this hybrid, which has been known since 17441, in colour more nearly resembles the cock of Tetrao tetrix than that of Tetrao urogallus, whilst the female in this respect is less characteristic and resembles the hens of both species. In shape its hybrid nature is indicated by the form of the tail; in size it is intermediate between both parents, so that both sexes are larger than the father, and the male is even larger than the mother. The other hybrid, the result of a connection between Tetrao tetrix and Lagopus albus, which is called in Norway and Sweden " Rype- Orre," is much rarer, and specimens are still desiderata in most museums. Tbe origin of this hybrid, its habits, and its places of resort are as yet partially, if not wholly, obscure. Its winter plumage is the only one which is generally known, whilst the spring or summer plumage is all but unrecorded. 1 Kgl. Vet.-Akad. Handl. Stockholm, 1744, p. 181. |