95 



PLATE XXXVIII. 



HYMENIACIDON DUJABDINII, Bowerbanfc. 



Vol. ii, p. 224, ' Mon. Brit. Spongiadse.' 



Fig. 1. Represents the specimen found about two 

 miles north of Scarborough. Natural size. The dark 

 front surface represents the sponge ; the upper white 

 surface is Nullipora polymorplia. 



Fig. 2. One of the skeleton spicula. X 250 

 linear. 



Fig. 3. One of the internal defensive spicula. 

 X 250 linear. 



Fig. 4. A valve of Pecten varius, the greater 

 portion of which is covered with H. Dujardinii. From 

 Tenby. Natural zize. 



HYMENIACIDON CELATA, Bowerbanlc. 



Vol. ii, p. 212, ' Mon. Brit. Spongiadse.' 



Fig. 5. Represents a small boulder of limestone 

 from Tenby, with innumerable perforations, each of 

 which is occupied by H. celcda. Natural size. 



Fig. 6. An average-sized skeleton spiculum. X 350 

 linear. 



HALICHONDBIA GELATINOSA, Bowerbank. 



Vol. ii, p. 222, ' Mon. Brit. Spongiades.' 



Fig. 7. Represents the type-specimen from Dourie 

 Yoe, Shetland. Natural size. 



Fig. 8. A full-sized spinulate skeleton spiculum. 

 X 123 linear. 



HYMENIACIDON BUCKLANDI, Bowerbank. 



Vol. ii, p. 226, ' Mon. Brit. Spongiadse.' 



Fig. 9. Represents the specimen from the rocks of 



