198 
Figs. 1, 2. Neusina Agassizi, nat. size. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 
EXPLANATION OF THE PLATE. 
The edge of the last chamber ; nat. size. 
Part of the surface, showing its wrinkles and pores ; in reflected light. x 4}. 
Transverse section, showing the partitions and the small irregular chamber- 
lets, the former made up chiefly of ovoid silicious bodies; in transmitted 
light. Xj. 
Network of chitinous threads forming the stroma of the test, after removal 
of the sand. x49. 
The lower part of an appendicular tube, cleared from sand, showing its 
structure of bundles of threads. X$. 
Transverse section of such a tube. X4. 
Colored sketch, from a fresh specimen, made on board the “ Albatross” 
by M. Westergren. 
