133 



PLATE LIl. 



IsoDiGTYA PALMATA, Bowerbank. 



Vol. ii, p. 311, ' Mon. Brit. SpongiadaB.' 



Fig. 1. — Re23reseiits the specimen of this species 

 designated as the " Mermaid's Glove " sponge, dredged 

 at the Orljney Islands, by Mr. McAndrew, in 1851. 

 Half the natui'al size. 



Fig. 2. — A small portion of the reticulated skeleton 

 of the sponge, illustrating its structural peculiarities. 

 X 80 linear. 



Figs. 3, 4, 5. — ^Three of the remarkable equi-ancho- 

 rate, retentive spicula, with flexuous terminations. 

 X &^':>Q linear. 



Fig. 6. — One of the minute equi-anchorate retentive 

 spicula, with siliceo-membranous terminations. X 666 

 linear. 



Fig. 7. — One of the skeleton spicula. 



