J. G. WALLER ON A NEWLY DISCOVERED BRITISH SPONGE. 223 



DESCRIPTION OF PLATE VIII. 



A drawing of the sponge itself, as preserved, would scarcely convey its 

 special characters, as it is partially obscured by extraneous matters, frag- 

 ment of shell, &c. The following details will, however, illustrate the 

 structure : — 



Fig. 1. — Fasciculi of skeleton spicules ; terminations concealed. 

 Fig. 2. — Skeleton spicule. Size, 30-4000ths of an inch. 

 Fig. 3. — Portion of membrane showing the intricate interlacing of 

 bihamate spicules and a forcepiforrn spicule at base (a). 



Fig. 4. — Small contort bihamate spicule. Size, 7-4000ths of an inch. 

 Fig. 5.— Large „ „ „ „ 17-4000ths „ 



Fig. 6. — Large tridentate equi-anchorate spicule showing a remarkable 

 development at base like an expansion of additional fluke. A minute spine 

 also seems to project from the central tooth of the upper fluke. Size, 

 5-4000ths of an inch. 



Fig. 7. — Large bidentate equi-anchorate spicule. Flanges of flukes of 

 unequal length. Size, 5-4000ths of an inch. 



Figs. 8, 9. — Two views of small bidentate equi-anchorate spicule. Size, 

 3-4000ths of an inch. 



Fig. 10. — Arcuate, entirely spined spicule. Size, 20-4000ths of an inch. 

 Figs. 11, 12. — Forcepiforrn spicule showing two sides, one having a 

 bulbous inflation at the arch, incipiently spined. Size, 6-4000ths of an inch. 

 Fig. 13. — Group of spicules. Entirely spined arcuate spicule ; forceps 

 formed at base of its arm (a), another developing on membrane, &c, &c. 



Fig. 14. — Another group with skeleton spicule and reverse of the forceps 

 form. Figs. 1, 2, 10, 13, 14 drawn to same scale. 



Fig. 15. — Forcepiforrn spicule from Eaperia cupressiformis, copied from 

 plate in Vol. xiv. of " Annals of Natural History, &c," 4th series. 

 (a) Bulbous termination of arms largely magnified. 



Fig. 16. — Ditto from Forcepia colonensis, copied from figure in above. 

 Spines omitted on one arm. Mr. Carter remarks that this is really not half 

 so long as that of Fig. 15. Its scale is l-12th to l-6000ths of an inch. 



Fig. 17. — Minute forcepiforrn spicule from sponge found by Mr. Carter 

 on the rocks at Budleigh Salterton, drawn by him from memory. (See 

 " Annals, &c," as above quoted). 



Fig. 18. — Forcepiforrn spicule from a sponge from Port Elliot, Australia. 

 It resembles that given by Dr. Bowerbank (" British Spongiadee," Vol. iii., 

 PI. XLIIL) from Halichondria forceps. Size, 5-2000ths of an inch. 



Fig. 19. — Small forcepiforrn spicule, given by Dr. Bowerbank, from a 

 sponge from Western Australia, but called by him " sub-spinulate arcuate." 

 (See "British Spongiadie," Vol. i., Plate VII., Fig. 173.) 



Fig. 20. — Entirely spined forcepiforrn spicule, with bulbous inflations at 

 ends of arms, from an unknown exotic sponge, allied to Dysidea by taking 

 up extraneous particles of various spicules of other sponges. — N.B. The 

 magnifying power is different in several figures which are not to the same 

 scale. 



