APPENDIX B. 
DESCEIPTION OF A NEW SPECIES OF PSMIMAPLIDIUM. 
After the greater part of this Eeport had been printed and the plates finished, I 
received from the Challenger Office a small bottle containing some sandy masses obtained 
on the north coast of Australia, which proved on examination to be specimens of a new 
species of the genus Psammaplidium. As it was too late to insert this species in its 
proper place in the body of the Eeport, a description of it is given here. 
Psammaplidium pyriforme, n. sp. 
External Appearance. — The shape of the colony is rudely pyriform. The upper end 
is wide and usually flattened, while the lower part tapers to a small area of attachment. 
The sides vary in shape, they may be convex or almost flat. The surface is irregular and 
rough. The colour is yellowish-grey. 
The length is 2 cm., the greatest breadth is 1‘3 cm., and the thickness is 1 cm. 
The Ascidiozooids are not large. They are placed at right angles to the ujDper surface 
of the colony, but do not show any regular arrangement in systems. The body is 
elongated antero -posteriorly, and the post-abdomen is distinctly separated from the 
anterior part. 
Tlie Test is very stiff and hard but brittle. It is densely crowded with sand-grains 
and other foreign particles. The matrix is clear and transparent. The test cells are 
small and inconspicuous. 
The Mantle is thick, and the musculature is very strong. The muscle bands run 
chiefly in a longitudinal direction. 
The Branchial Sac is long and narrow. The stigmata are numerous. They are of 
fair size and are arranged regularly. 
The Endostyle is large and conspicuous. 
The Tentacles are numerous but rather short. They are all of one size. 
The Alimentary Canal forms a narrow loop. The stomach is globular and smooth- 
walled. 
The Post- Abdomen is long and narrow. 
