days after ligaturing the ducts (Experiments 1, 2, 5, &c.), the bile ducts were found so greatly increased in size that on making a section of the liver, even the so-called bile capillaries could be seen by the naked eye without the aid of injection. In all cases where the blood vessels were filled with injection, and the liver hardened in a solution of bichromate of potassium, free spaces were found between the blood capillaries and the liver cells. These appeared to be the perivascular lymph spaces of MacGillavry* and Budge. The enlargement of the perivascular lymph spaces seem to have taken place at the cost of the liver cells, for not only did the cells themselves appear to be much smaller, but the nuclei of the neighbouring hepatic cells appeared to be closer together than normal. Three conclusions may apparently be drawn from the results obtained from these experiments: Firstly. That bile existing in the bile ducts can only reach the blood through the intervention of the lymphatics. Secondly. Seeing that lymphatics surround the liver blood vessels, one is forced to believe that bile pigment and bile acid cannot pass through the endothelium of the blood capillaries in the liver; or, perhaps, even throughout the body. The fact that bile reaches the blood when it has escaped into the peritoneal cavity is no argument against this view. For in that case it would reach the blood through the lymphatics of the diaphragm. Thirdly. After the left thoracic duct has been ligatured for some time, collateral lymphatics are opened up, or developed, leading into the right innominate vein. VII. "On the Composition of Hæmocyanin." By A. B. GRIFFITHS, Ph.D., F.R.S. (Edin.), F.C.S., &c. Communicated by M. FOSTER, Sec. R.S. Received March 16, 1892. Dresden :-K. Leop.-Carol. Deutsche Akademie der Naturforscher. * MacGillavry, "Zur Anatomie der Leber" (Wien, Akad. Sitzber.,' vol. 50, Abth. 2, 1865, p. 207). + Budge," Ueber die Lymphgefässe der Leber" (Berichte der K. Sächs. Gesell.,' 1875, p. 161. Transactions (continued). Bulletin of Miscellaneous Information. No. 63. 8vo. London 1892. London :-British Association. 8vo. London 1892. The Director. Report of the Sixty-first Meeting. The Association. British Astronomical Association. Journal. Vol. II. No. 4. 8vo. London 1892. British Museum. Catalogue of the Birds. The Association. Vol. XX. 8vo. The Trustees. London 1891. The Society. Memorias y The Society. 1891. Mexico-Sociedad Científica "Antonio Alzate." Revista. Tomo V. Nos. 3-4. 8vo. México 1892. Newcastle :-North of England Institute of Mining and Mechanical Engineers. Transactions. Vol. XLI. Part 1. Newcastle 1892. New York:-American Museum of Natural History. Vol. IV. Pp. 17-32. 8vo. [New York] 1892. Odessa :-New-Russian Society of Naturalists. 8vo. The Institute. Bulletin. The Museum. Memoirs. Vol. Memoirs of the 8vo. Odessa The Society. Proceedings. Philadelphia :-American Philosophical Society. The Society. Vol. VI. Pisa-Società Toscana di Scienze Naturali. Memorie. XLIX. No. 1. 8vo. Stockholm 1892. 1891. 8vo. Toronto. The Academy. Transactions. The Society. Anzeiger. The Academy. Vienna:-Kaiserliche Akademie der Wissenschaften. 1892. No. 7. 8vo. Wien 1892. Observations and Reports. Dorpat:-Meteorologisches Observatorium. Beobachtungen. 1890. 8vo. Dorpat 1892. Meteorologische The Observatory. Edinburgh :-Royal Observatory. 4to. The Observatory. Report of the Medical Offi- [Sheets.] Edinburgh 1892. London:-Local Government Board. cer. 1890. 8vo. London 1891. Solar Physics Committee, Department of Science and Art. Measures of Positions and Areas of Sunspots and Faculæ on Photographs taken at Greenwich, Dehra Dun, and Melbourne; with the Reduced Heliographic Longitudes and Latitudes. 1878-1881. 4to. London 1891. The Committee. Melbourne :-Observatory. Monthly Record. September-October 1891. 8vo. Melbourne. The Observatory. St. Petersburg-Physikalisches Central-Observatorium. Annalen. Jahrg. 1890. Theil 2. 4to. St. Petersburg 1891. The Observatory. Sydney-Geological Survey of New South Wales. Memoirs. Paleontology. No. 8. 4to. Sydney 1891. The Department of Mines, Sydney. Observatory. Meteorological Observations. September, 1891. 8vo. Sydney. The Observatory. Windsor (N.S.W.):-Results of Meteorological Observations made at the Private Observatory of John Tebbutt, The Peninsula, Windsor, N.S.W., in the years 1886-1890. 8vo. Sydney 1891. Mr. Tebbutt. Zurich: Schweizerische Meteorologische Central-Anstalt. Annalen. 1889. 4to. Zürich. The Institute. "The Nature of the Shoulder Girdle and Clavicular Arch in Sauropterygia." By H. G. SEELEY, F.R.S., Professor of Geography, King's College, London. Received January 18,-Read February 18, 1892. I. Nomenclature of the bones. II. Clavicular arch in Plesiosaurida. III. Clavicular arch in Elasmosauridæ. IV. Classification. I. THE NOMENCLATURE OF THE BONES OF THE SHOULDER GIRDLE. § 1. In Ichthyosauria. The Sauropterygia and Ichthyosauria having formerly been combined in the group termed Nexipoda or Enaliosauria, it has been rather assumed than proved that the bones which form the shoulder girdle in those orders are homologous. The Ichthyosaurian shoulder girdle was well figured by Sir E. Home (Phil. Trans.,' 1818, Part I) and Cuvier ('Oss. Foss.,' Pl. 258). Figures by other authors agree substantially (Huxley, Anatomy of Vertebrates,' p. 244) in showing (1) that the coracoids meet ventrally in the median line; (2) that there is a notch on the anterior margin of the coracoid between the median anterior cartilaginous border of the bone and the scapula, and this notch varies in depth and width with the species; (3) the scapula is directed outward, upward, and forward; (4) its articular end has a posterior part which contributes with the coracoid to form the glenoid cavity for the head of the humerus, a median part, which articulates with the anterior articular edge of the coracoid, and an anterior surface, which does not differ in its cartilaginous articular aspect or thickness from the middle portion, but which looks inward without any bony element of the shoulder girdle to articulate with it. This condition has not been explained. At one time I doubted the existence of such a surface in the undisturbed skeleton ("Pectoral Arch, &c., of Ophthalmosaurus," Geol. Soc. Quart. Journ.,' December, 1874, p. 698), and some subsequent writers have restored the shoulder girdle as though no such surface existed (J. W. Hulke, "Presidential Address, Geol. Soc., 1883," p. 19, copied by R. Lydekker, 'Cat. Foss. Rept. and Amph. Brit. Mus.,' Part II, 1889); (5) the scapula carries the rod-like clavicle upon the anterior margin of the bone, and from the posterior or ventral surface of the clavicles the median bar of the interclavicle is prolonged backward ventrally upon the coracoid bones. Since 1874 I have examined most of the Ichthyosaurian skeletons from English and German strata without finding a specimen which VOL. LI. K leads me to doubt the substantial accuracy of the early interpretations of Home, Buckland, and Cuvier, in regarding the scapula as extending an articular surface inward and forward towards the pre-articular portion of the coracoid. Various circumstances lead me to suggest that the notch on the anterior margin of the coracoid is a portion of the precoracoid foramen; that the precoracoid element of the shoulder girdle was cartilaginous in Ichthyosaurus; and that this cartilage usually articulated with the part of the scapula anterior to the external articulation of the coracoid, and also with the anterior inner processes of the coracoids, so as to complete the precoracoid foramen anteriorly. Among the reasons which suggest this interpretation are: (1) It accounts for the structure of the shoulder girdle, and explains its homology; (2) it brings the shoulder girdle of Ichthyosaurus into harmony with Nothosaurus, in which there is a similarly incomplete (precoracoid) foramen and similar cartilaginous surfaces of coracoid and scapula in close juxtaposition; (3) it brings the shoulder girdle of Ichthyosaurus into harmony with that of the Anomodontia, because they correspond in the form of the scapula, the positions and forms of the clavicles, interclavicles, and coracoids; so that, if the Anomodont precoracoid were unossified, the differences from Ichthyosaurus would be small, except that some of the Anomodonts (Pareiasaurus) develop an epiclavicle of Labyrinthodont type. On this evidence a cartilaginous precoracoid is shown in the restoration now given. FIG. 1.-Shoulder girdle of Ichthyosaurus. cor., coracoid; sc, scapula; ? pc, precoracoid, supposed to have been cartilaginous; cl, clavicle; i.cl, interclavicle. Before the Enaliosauria were subdivided, the bone which is here named interclavicle was regarded by Sir E. Home as homologous with the interclavicle of Ornithorhynchus, but it is named episternum by Cuvier, Sir R. Owen, and some recent writers like K. von Zittel. To the best of my belief the episternum was identified as being the interclavicle by Professor Huxley. My own earliest use of the term in relation to Ichthyosaurus is in 1869 ( Index to Fossil Remains, &c., Woodw. Museum'). If the ossifications are membrane bones, they are rightly classed as clavicles; if they are cartilage bones, they may be connected with the sternum, and take a sternal name. Each of |