61 



PLATE XXIV. 



MiCBOOiONA SPENgLENTxi, Boionrhanlc. 



Vol. ii, p. 132, ' Mon. Brit. Spongiadte.' 



i^'ig. 1. — -Ptopresents a valve of Pecten opicularis 

 covered with a thin coat of M. spiuulenta, all the dark 

 portions between the ribs of the shell having the 

 appearance of the wet pile of a brown cotton velvet. 

 The white patch on the middle of the valve is Celle- 

 pura pumicosa. The specimen is from Weymouth 

 Bay, near the wreck of the Abergavenny. Natural 

 size. 



Fig. 2. — From one of the sul)-clavate, cylindrical, 

 tension spicula of the dermal membrane. X 250 

 linear. 



Fig. 3. — An attenuato-acute, entirely spined, skeleton 

 spicnlum ; the base lieing profusely spinous. X 250 

 linear. 



Fig. 4. — One of the short attenuato-acuate, entirely 

 spined, internal, defensive spicula. X 250 linear. 



Fig. 5. — One of the l)identate, inequi-anchorate, 

 retentive spicula. X 1250 linear. 



Fig. 6. — An unipocilate, retentive spiculum. X 1250 

 linear. 



MlOEOGloNA prjTMOSA, Bmverban]:. 



Spongia plumosa, Montagu. 



Halichondna plumosa, Johnston. 



Hijmeniacidon phimosa. Bowerbauk. ' Mon. Brit. Spong.,' 



vol. ii, p. 196. 

 Microciona carnosa, Bowerbank. ' Mon. Brit. Spong ,' 



Tol. ii, p. 133. 



The sponges described by me in vol. ii, pp. 195 and 

 133, are decidedly the same species, and both belong 

 to the genus Microciona. 



I have fallen into this error through having examined 

 and described the first specimens of this sponge 



