Synopsis of the contents of the museum of the Royal College of Surgeons of England.

  • Royal College of Surgeons of England
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: Synopsis of the contents of the museum of the Royal College of Surgeons of England. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    lity the principal food of the whale. They swim by means of a pair of fins developed from the side of the neck. Some species are shell-less; but others are provided with a fragile, translucent, and symmetrical shell, of conical, ventricose or spirally coiled form, several examples of which are seen in Floor Cabinet D, Compartment 4, E 350 to 355. Class Gasteropoda. The animals of this large and important class have a distinct head, and move by means of a flat, broad muscular disc on the under surface of the body, called the foot. Some are aquatic in their habits, and respire by means of gills; while others (as the common Snail, E 446 [F.]) breathe by means of a pulmonary sac. The shell, when present, is generally univalve, although in some (as the Chitons, E 456 to 472 [F.]) it is composed of several pieces (multivalve). In many the mouth of the shell is closed when the animal retires within it, by an operculum or lid. This is attached to the dorsal sur- face of the posterior part of the foot, and is composed of horny material (as in E 1037 to 1041 [F.]), or of a dense shelly substance (E 1042 to 1050 [F.]). It always exhibits more or less of a spiral development, and by some authorities is considered to be the analogue of the dextral valve of the Lamellibranchiata. The principal modifications of structure and mode of growth of shells of Gasteropoda are well illus- trated by the series of sections (E 1067 to 1098 [F.]). Class Cephalopoda. The Cephalopoda are the most highly organized of the Mollusca, and are distinguished externally by the arm-like tentacles—organs of motion and prehension—placed like a crown around the head. The form and situation of the shell in animals of this class vary exceedingly. In some it is external and chambered, as in the Pearly Nautilus (Nautilus pompilius), E 1051 [F], and its allies the extinct Ammonites. In others it is external, but not chambered, as in the Paper Nautilus (Argonauta argo), E 1056 to 1059 [F], in which c