Ill 



PLATE XLV. 



HALICHONDEIA DICKIEI, Bowerbank. 



Vol. ii, p. 253, ' Mon. Brit. Spongiadse.' 



Fig. 1 . Represents the type-specimen received from 

 Dr. Dickie. Natural size. 



Fig. 2. A mucronato- cylindrical spiculum, from the 

 dermal membrane. X 250 linear. 



Fig. 3. One of the subclavate, hastate spicula, 

 from the dermal membrane. X 250 linear. 



Fig. 4. An acuate, entirely-spined spiculum, from 

 the skeleton. X 250 linear. 



Fig. 5. One of the large, bidentate, equi-anchorate, 

 retentive spicula. X 530 linear. 



Fig. 6. A large, tridentate, equi-anchorate spiculum, 

 from the inner surface of the dermal membrane. 

 X 530 linear. 



HALICHONDEIA GEANULATA, Bowerbanlc. 



Yol. ii, p. 262, ' Mon. Brit. Spongiadse.' 



Fig. 7. Represents the type- specimen received from 

 the late Mr. Joshua Alder. Natural size. 



Fig. 8. One of the submucronate cylindrical spicula, 

 from the dermal membrane. X 250 linear. 



Fig. 9. A large, bidentate, equi-anchorate, retentive 

 spiculum, from the dermal membrane. X 530 linear. 



Fig. 10. A small, tridentate, equi-anchorate, re- 

 tentive spiculum, from the dermal membrane. X 530 

 linear. 



Fig. 11. One of the aeuate, entirely and incipiently- 

 spined skeleton spicula. X 250 linear. 



Figs. 12 and 13. Two of the attenuato-acuate, 

 entirely-spined, internal, defensive spicula. X 250 

 inear. These spicula differ greatly in size. The two 



