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Show 1899.] ON THE OSTEOLOGY OF PH0R0RHAC0S INFLATES. 437 between the radius and the ulna, and articulating with the former,... its position was distad from the ligament connecting the radius and ulna, but proximad from the wrist fissure" (Handgelenkspalte).1 To judge from the figure, this ossicle of the Phascolomys is situated slightly more proximad than in the Rodents and in Lepidolemur. It is not for m e to decide whether the ossicle of the Primates, Rodents, and Phascolomys is really the homologue of the human so-called intermedium antebrachii, which last in the embryo as well as in the adult is situated more ulnad, and-when it does not disappear by reduction-becomes fused with the proc. styloid, ulnae, or secondarily imbedded in the meniscus.2 The alternative is, that the "intermedium antebrachii" of man may be, after all, the same element of human embryos which Thilenius has called ulnare antebrachii3, which corresponds to Pfitzner's pisiforme secundarium in the adult4, and is besides the homologue of the "ossiculum Dau-bentonii" of Hylobatcs and Lnuus\ To judge from Leboucq's 6 and Kohlbrugge's7 figures and descriptions, the ossiculum Daubentonii must be assigned to the carpus rather than to the antcbrachiuin. It seems to form, as a rule, the proximal portion of the pisiform of Mammals, except in man 8, and I consider it therefore as a marginal ulnare-the first, proximal, element of the fifth ray. Mr. C. W . Andrews read a paper on the osteology of one of the great extinct birds of Patagonia, Phororhacos infiatus. He described in detail the structure of the skull and skeleton, and compared them with various recent forms of birds. The evidence as to the affinity of this type was somewhat conflicting, but on the whole pointed to a relationship with the Gruiformes, as had been previously suggested by the author. It seemed probable that the aberrant Cariama was the nearest living representative of Phororhacos, being related to it somewhat in the same fashion as the small modern Armadillos are to such great extinct forms as Glyptodon and Panochthus. This paper will be published in full in the Society's ' Transactions.' 1 Morph. Arb. v. p. 10 (1895). 2 Morph. Arb. v. p. 7 (1895). 3 Met with in ten manus of five embryos, and situated palmad and ulnad from the proc. styl. ulnae, and proximad from the pisiform. See Morph. Arb. v. p. 470 (1896). 4 In five cases a proximal process of the pisiform was found. " Dieser Fortsatz war (in vier Fallen) proximal, und zugleich eher etwas dorsal als volar, gerichtet. Seine plane Flache stellt eine continuierliche Fortsetzung der Gelenkflache des Hauptstiicks dar; im Uebrigen war der Fortsatz ringsherum durch eine tiefe Einziehung abgesetzt." Morph. Arb. iv. p. 508 (1895). s Kohlbriigge, I. c. pp. 338, 339, pl. xvii. fig. 9 (1890-91). 6 Arch, de Biologie publ. par Van Beneden et van Bambeke, v. p. 83, pl. iv. fig. 28. 7 L.c. 8 Leboucq, I. c. p. 83. P R O C ZOOL. Soc-1899, No. XXIX. 29 |