The royal natural history . illustratesa sponge dredged by the Challenger, and knownas Esperiopsis cltallengeri, from six hundredand thirty fathoms, east of the Celebes. The largest specimens are about 8 inchesin height. From a solid, strong stem six or seven stalks are given off at gradually SINGLE-RAYED SPONGE, Axinella (nat. size).. SILICEOUS SPICULES OF MONAXONID SPONGES (magnified 200-:i00 diameters). TYPICAL GROUP. 543 increasing intervals from below upwards, and each bearing a hemispherical cup orladle, convex outwards. The in-current pores are on the concave, and the out-currenton the
The royal natural history . illustratesa sponge dredged by the Challenger, and knownas Esperiopsis cltallengeri, from six hundredand thirty fathoms, east of the Celebes. The largest specimens are about 8 inchesin height. From a solid, strong stem six or seven stalks are given off at gradually SINGLE-RAYED SPONGE, Axinella (nat. size).. SILICEOUS SPICULES OF MONAXONID SPONGES (magnified 200-:i00 diameters). TYPICAL GROUP. 543 increasing intervals from below upwards, and each bearing a hemispherical cup orladle, convex outwards. The in-current pores are on the concave, and the out-currenton the convex surface. To this order belongs the Neptunes cup sponge (Poterium),attaining a height of 3 or 4 feet. It includes also the boring-sponges (Cliona), inwhich the skeleton consists of scattered pin-shaped spicules. To compensate forthe inefficient support, the sponge excavates into limestone, chalk, or shells. Greatimportance is attributed to the destructive power ofthese sponges by Prof. Schmidt, who points out that --:?-?.:•>._ considerable portions of the coasts of the Mediter- lranean consist of limestone, the disintegration of Iwhich has been greatly hastened by the operation ofboring-sponges. In many parts the outlines of thecoast have consequently been much altered, and alongthe Dalmatian shore, for a distance
Size: 906px × 2758px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectnaturalhistory, booksubjectzoology
