288 Mr. A. Adams on the Animal of Umbonium vestiarium. 
scapus pedalis, basi 2 lin. crassus; folia radicalia plurima, rosu- 
lata, 24-34 poll. long., 1 lin. lat.; folia scapi breviora ; capitu- 
lum 8 lin. diam.; corolla 2 lin. long., omnino alba, tubo at- 
tenuato, palez libere, lineari-setacee ; ovaria libera, profunde 
5-angulata, et, ut in ultima specie, valde hyalina, dentibusque 
5 acutis coronatis*. ; 
[To be continued. | 
XXXIX.—On the Animal of Umbonium vestiarium. 
By Artuur Apams, F.L.S. &c. 
SiNcE writing my notice of the animal of Umbonium giganteum, 
which I observed at Hakodadi in Japan, I have had an oppor- 
tunity, in the north of China, among the Mia-tau Islands, at the 
entrance of the Gulf of Pe-chili, of observing Umbonium vestia- 
rium, Linn. (Rotella lineolata, Lamk.), m a living state, and have 
succeeded in procuring a correct figure of the architect of a shell 
which, like that of Phorus and Terebellum formerly, has long 
been familiar to naturalists, but the true position of which, in a 
natural arrangement of Mollusca, has remained doubtful. 
The animal may be found, at low-water spring-tides, in vast 
numbers covering the sandy patches between the trachytic and 
basaltic rocks which compose the basis of the islands of this 
group. Some few individuals, half-covered with sand, may be 
seen on the surface; but the majority must be sought for under 
the surface of the wet sand, by following the traces they leave, 
They burrow rapidly by means of their broad and flexible foot. 
which they press downwards, and scoop out a bed for the shell, 
throwing up the sand from under it. The use of the curious 
fimbriated funnel-shaped organ formed from or appended to the 
modified eye-peduncle of the left side is now obvious: it serves as 
a means of communication between the surrounding water, which 
fills the cavity in which the Umbonium is lodged, and the gills 
—ejecting the particles of sand, and performing the part of a 
true siphon. 
On a level surface the animal marches in a deliberate manner, 
taking long strides as it seems, the onward movement being 
effected by alternate lateral undulations of the foot, one side 
advancing at a time. As it walks, the caudal extremity moves 
from side to side in an undulatory manner. The Umbonium is 
very sensitive to alarm, shrinking at any sudden noise or vibra- 
tion. When placed on its back, it soon rights itself, by placing 
its foot under the shell, and will often turn over several times. 
The muzzle is short and rounded, and of a pale brown, the 
extremity being pellucid, and the margins furnished with ra- 
* This species is represented in Plate 47 c. 
