BUITISH SPONGIADjE. 157 



Oscula minute, dispersed, numerous. Pores incon- 

 spicuous. Dermal membrane pellucid, abundantly 

 spiculous, dispersed, same as those of the skeleton. 

 Skeleton : spiculasubfusiformi-acerate, large and rather 

 long, and the same form short and slender. Gem- 

 mules membranous. 



Colour. — Alive, scarlet, dried, light gray. 

 Locality. — Salcombe Bay, Devonshire, Mr. Alder. 

 Examined. — In the dried state, 



I received two specimens of this sponge from my friend, 

 Mr. Joshua Alder, of Newcastle-on-Tyne. In the box con- 

 taining them there was also a small specimen of Hymenia- 

 cidon caruncula, from the same locality, and from the 

 external appearances of the two species it would have been 

 impossible to have distinguished the one species from the 

 other ; and it would appear that the same difficulty exists 

 in the living state. On referring to Mr. Alder regarding 

 the colour when alive, he wrote as follows : " I have no re- 

 collection about the sponges I got in Salcombe Bay, and 

 the colour was the only memorandum I preserved. As 

 I had put them together, I must have supposed them to be 

 the same species, and I have therefore no doubt that they 

 would be similarly coloured." This similarity in colour 

 would be very likely to mislead a casual observer, but the 

 difference in form at once distinguishes the species. In 

 the dried state H. coccinea and H. Thomasii might be mistaken 

 for each other if external characters alone were referred to, 

 but a comparison of the spicula of the two species readily 

 distinguishes them, those of the latter species being nearly 

 twice the size of the spicula in the former one. 



Immediately beneath the dermal membrane there was 

 a considerable number of membranous gemmules, variable 

 in size, and each containing the usual granular vesicles. 



