359 
to our Knowledge of the Spongida. 
Schmidt’s Sceptrella regalis seems to me to be an anomaly, 
since there are anchorates of both kinds present, viz. equi- 
and inequianchorates. May not these be adventitious ?—just 
as we find the skeleton- and smooth spirular spicule of, to me, 
Hancock’s Gliona northumhrica (Ann. 1867, vol. xix. p. 237, 
pi. vii. fig. 1) mixed with or appropriated by an Esperia , 
forming part of Kent’s Rhaphidotheca Mar shall-Hallii (Ann. 
1870, vol. vi. p. 222, pi. xv. figs. 3 and 6). 
It remains to be seen whether Corticium Wallichii , which 
I conjectured, from the form of the skeleton-spicule only, to 
belong to the Gumminida, does so or not. 
That Sceptrella may be a Spinispirula under another form, 
the flesh-spicules of Latruncula corticata, (PI. XXVII. fig. 
4, a, h , c) plainly demonstrate. 
EXPLANATION OF PLATES. 
Plate XXVIII. 
Fig. 1. Trachycladus leevisjriridifer , n. sp. (natural size), a, stem; b, 
branches. 
Fig. 2. The same. Skeleton-spicule (scale l-24th to 1-G000th inch). 
Fig. 3. The same. Flesh-spicule, spirular (same scale). 
Fig. 4. The same. Flesh-spicule, cylindrical (same scale). 
Fig. 5. The same. Length of spicule on scale of l-12th to l-1800th inch, 
for comparison. 
Fig. 6. Suberites spinispirulifer, n. sp. Skeleton-spicule (scale 1-12th to 
l-1800th inch). 
Fig. 7. The same. Flesh-spicule, spinispirulate. a, same scale; b, more 
magTiified, to show the spination. 
Fig. 8. Suberites angulospiculatus , n. sp. a, smaller and more angulated 
form; b, larger and less angulated form. Scale l-24th to 
1-G000th inch. 
Fig. 9. Suberites fuliginosus, n. sp. a, smooth skeleton-spicule; b, spinous 
skeleton-spicule. Scale l-24th to 1-G000th inch. 
Fig. 10. Stellettinopsis corticata, nov. gen. et sp. (nat. size), a, vents ; 
b, base. 
Fig. 11. The same. Skeleton-spicule (scale l-24th to l-1800tk inch). 
Fig. 12. The same. Flesh-spicule, stellate, a, on scale of l-48th to 
1-6000th inch ; b, the same, more magnified. 
Fig. 13. The same. Flesh-spicule, bacilliform, spinous, a , on scale of 
l-48th to l-60U0th inch ; b, the same, more magnified. 
Fig. 14. The same. Quartz grains in the cortex. 
Fig. 15. The same. Vent and portion of the surface, magnified respec¬ 
tively and relatively, to show : — a, aperture in the centre of the 
sphinctral diaphragm; b, elevated border; c, form of the con¬ 
voluted dermal sarcode; d, the same, more magnified, showing 
the position of e, the quartz grains. 
Fig. 16. Stellettinopsis simplex , n. sp. Skeleton-spicule (scale l-24th to 
l-1800tk inch). 
Fig. 17. The same, a, flesh-spicule, stellate (scale l-48th to 1-6000th 
inch) ; b, the same, more magnified; c, arm, still more magnified, 
to show the raicrospi nation. 
Fig. 18. The same, a, flesh-spicule, sceptrella; b } the same, more 
magnified. Scale 1 -24th to 1-G000(h inch. 
