On the Euplectella aspergillum, Owen; or "venus's Flower Basket," A species of sponge belonging to the alcyonoid family; and a notice of the Iiyalonema or "Glass Rope" sponge.

Abstract

Sponges assume a great variety of forms, some are cylindrical and cup-shaped, others are flattened, spherical, and finger shaped, varying in size from small specks to gigantic dimensions, the latter exemplified in the so-called "Neptune's Cup," (Thalassema neptuni) a specimen of which is in the Museum of the Society. Some of the sponges display a great variety of rich colours, from bright scarlet and mauve, to pale yellow and rose, but the beautiful and delicate tints change when exposed to the air to a dull brownish hue. Sponges are formed of a soft glairy substance termed sarcode, which envelopes a skeleton composed of silicious, calcareous, or horny material. The first exemplified by the Euplectella, Hyalonema, Holienia, Rossella,&c.; &c.; the second by the genus Grantia, and the last by the common sponge (Spongia communis) forming an elastic substance extensively employed for domestic purposes.