[21] This Crab has an elongated spine-like tail, the use of which was long misunderstood. Dr. J. Gray was shown at the Liverpool Museum some living King Crabs, and the use they made of the tail-like appendages. When turned over on their backs, he saw them bend down the tail until they could reach some point of resistance, and then employ it to elevate the body, and regain their normal position. Dr. Gray states that they never have been seen to use this tail for the purpose which has been often assigned to it--that is, for leaping from place to place by bending it under the body, like the toy called a "spring-jack," or "leaping frog." [22] American Journal of Science and Art. [23] W. C. Linnæus Martin, F.L.S. MUSICAL LIZARDS. A small Lizard, lately brought home from the Isle of Formosa by Mr. Swinhoe, is decided to be a new species by Dr. Günther, of the British Museum. Mr. Swinhoe found the eggs of this Gecko, or Lizard, in holes of walls or among mortar rubbish. They are round, and usually lie several together, resembling eggs of ordinary Lizards. The young, when first hatched, keep much under stones in dark cellars, where they remain until they attain about two-thirds of the adult size, when they begin to appear in public to catch insects, but evincing great shyness of their seniors. Mr. Swinhoe states that on the plaster-washed sides of his bedroom, close to the angle of the roof, every evening when the lamp was placed on the table below, four little Musical Lizards used to make their appearance and watch patiently for insects attracted by the light. A sphinx or a beetle buzzing into the room would put them into great excitement, and they would run with celerity from one part of the wall to the other after the deluded insect as it fluttered in vain, buffeting its head, up and down the wall. Two or three would run after the same insect, but as soon as one had succeeded in securing it, the rest would prudently draw aloof. In running over the perpendicular face of the wall they keep so close, and their movements are made so quickly, with one leg in advance of the other, that they have the appearance at a distance of gliding rather than running. The tail is somewhat writhed as the body is jerked along, and much so when the animal is alarmed and doing its utmost to escape; but its progress even then is in short runs, stopping at intervals and raising its head to look about. If a fly perch on the wall it cautiously approaches to within a short distance, then suddenly darts forwards, and with its quickly-protruded, glutinous tongue, fixes it. Apart from watching its curious manoeuvres after its insect-food, the attention of the most listless would be attracted by the singular series of loud notes these creatures utter at all hours of the day and night, more especially during cloudy and rainy weather. These notes resemble the syllables "chuck-chuck," several times repeated; and, from