166 A MONOGRAPH OF THE 



Colour. — 'In the dried state, cream white. 

 Habitat. — Surface of stones between tide-marks, Lerwick, 

 Rev. A. M. Norman. 



Examined. — In the dried state. 



I received seven specimens of this sponge, spread out and 

 dried on paper, from the Rev. A. M. Norman, who found it 

 on stones at Lerwick. The largest measured about two 

 and a half inches long, by nearly two inches wide, and in 

 its dried state it was scarcely thicker than the piece of stout 

 paper to which it was attached. In general appearance the 

 specimen very closely resembled large patches of stout 

 animal membrane, such as those of the thinnest portion of 

 the diaphragm of a sheep. 



There is a great paucity of structural characters in this 

 species. No other forms of spicula appear to exist in it 

 than those of the skeleton, and the difference in size and 

 proportions of the spicula of the skeleton and those of the 

 dermal and interstitial membranes is scarcely to be recog- 

 nised. It is fortunate that its external characters are 

 strikingly different from those of the species to Avhich it is 

 most nearly allied in structure. 



II.Hymeniacidon caruncula, BoKerbank. 



Sponge. Coating, thick ; surface uneven, but smooth. 

 Oscula, simple, small, dispersed, few. Pores incon- 

 spicuous, minute. Dei'mal membrane pellucid, thin, 

 abundantly spiculous ; spicula acuate, slender, irregu- 

 larly dispersed, very numerous. Skeleton. Spicula 

 acuate, rather stout. Interstitial membranes, tension 

 spicula acuate, slender. 



Colour. — Alive, from light to deep orange. 



Habitat. — St. Katherine's Cave, Tenby ; Guliot Caves, 

 Sark ; Hastings ; Mill Bay, near Land's End, Cornwall, 

 J. S. Bowerbank; Bantry Bay, Ireland, Rev. A. M. 



