| OCR Text |
Show 1876.] MR. J. W. CLARK ON DELPHINUS ALBIROSTRIS. 689 into 7 cervical, 14 dorsal, 24 lumbar, and 45 or 46 caudal. These latter are difficult to count accurately, as the last of the series are mere specks of cartilage. The first two cervical vertebrae are ankylosed ; the remaining five are free. These have each a superior and an inferior transverse process, with the exception of the seventh, in which the inferior process is absent. These processes are directed forwards and overlap each other. Those of the fifth vertebra are the least developed. The superior process of the seventh is extremely large, and overlaps those of the fourth, fifth, and sixth completely. There are fourteen pairs of ribs. The first six have long necks, reaching in each case to the articular surface on the side of the vertebra in front of that to which the tubercle is attached. At the seventh the necks cease suddenly, and it and the remaining ribs are attached by their tubercles only to the transverse processes of the vertebrae. This attachment becomes less and less close till the fourteenth rib is reached, which is attached by ligament nearly an inch in length to the transverse processes of the fourteenth and fifteenth thoracic vertebrae. There are nine pairs of sternal ribs. The first pair articulate to a facet upon the centre of the wings into which the sides of the first segment of the sternum is expanded ; the second at the junction of the first and second segments of that bone ; the third at the junction of the second and third segments; and the fourth, fifth, and sixth to the hinder end of the third segment. The spines of all the thoracic vertebrae are well developed and inclined backwards. This inclination gradually diminishes. The tenth vertebra has an absolutely vertical spine, as have all the lumbar vertebrae. In this portion of the column they are of great height, with well-developed metapophyses. The spines reach their greatest height at about the thirty second vertebra (counting from the first cervical), and cease at the seventy-fourth. The characters of the skull could not be ascertained, as it has not yet been sufficiently macerated. It measured 14| inches from the occipital condyles to the tip of the beak, which was 3 inches wide at the termination of the dental series. Length of dental series in a 23 23 straight line 5| inches. Dental formula 26_23. Unfortunately the lower jaw was carelessly macerated, and some of the teeth had fallen out, so that it was impossible to count them accurately ; but probably twenty-six might be set down as the number on both sides of the lower jaw. The teeth are all conical, recurved, sharp; those at the tip had not yet passed the gum. Viscera.-The tongue measured 6 inches in length by 2 in width. The tip was a sharply pointed triangle, on each side of which for a distance of nearly 2 inches it was deeply fimbriated. Some of these fimbriations were a quarter of an inch in length. Near the base were the orifices of numerous glands and several black spots. The stomach (Plate LXV.) differs somewhat both from that of the Porpoise (Phocana vulgaris) and that of the Pilot Whale (Globicephalus melas) described and figured by Prof. Turner*. * Journal of Anatomy, vol. ii. p. 72. |
