Cliona. 
Z. ^SCIDIOIDA. 
305 
face is porous or cellular, even, roughish, the pores roundish or pen- 
1 tagonal, distinct and separate, but not arranged in rows, or in any re- 
gular fashion ; the interior is irregularly cellular, and earthy. — None 
of the mineral acids have any effect on this substance, nor does it absorb 
water like a sponge, but when dropt into a glass of water, it sinks to 
' the bottom and lies there unaltered. No siliceous nor calcareous spi- 
! cula enter into its structure, but it seems to be entirely composed of 
| particles of sand cemented together with mud or clay. It has there- 
fore no character of a proper polypidom, although the conformation 
and regularity of its cells prove it to be the work of some gregarious 
animal. 
41. Cliona, # Grant. 
Character. Polypidom amorphous, fleshy , containing sili- 
ceous spicula and perforated with ramified canals. — Polypes mi- 
nute , retractile , placed in tubular papillce. 
1. C. celata. R. E. Grant, f 
Plate xlii. Fig. 5, 6. 
Cliona celata, Grant in Edin. New Phil. Journ. i. 78 • ii. 183, pi. 2, fig. 7, 
(the spiculum.) Flem. Brit. Anim. 516. Stark, Elem. ii. 421. 
La Clione cachee, Blainv. Actinolog. 527. 
Hab. In perforations of the shell of the oyster (Ostrea edulis) : 
abundantly in the oyster beds at Prestonpans, off Inchkeith, and in 
the roads of the Firth of Forth, Grant . 
This sponge-like zoophyte inhabits and fills up the worm-like holes 
in old oyster-shells. The part which projects beyond the orifice 
of the hole is papillary, about a line in height and about the same in 
breadth, of a yellowish colour, tubular, and either closed or widely 
open at the apex. In texture it resembles the Halichondria papil- 
* “ I have termed this genus Cliona, (from > claudo ), from its most ob- 
vious and remarkable property of retracting and shutting the papilla) when irri- 
tated ; and the above described species, the only one I have met with, is named 
celata, from its concealed and secure habitation within the substance of oyster- 
shells.” Grant. 
*f* Dr G. is a native of Edinburgh, where he received his education, and gra- 
duated M. D. in 1814, when he was President of the Royal Medical Society. 
His Thesis was “ de Circuitu Sanguinis in Foetu.” Shortly afterwards his at- 
tention was turned to natural history ; and his researches into the nature of 
sponges and zoophytes laid the foundation of that reputation which readily se- 
cured him the chair of Zoology and Comparative Anatomy in the London Uni- 
versity, on its first establishment, — a chair which he continues to fill with the 
most distinguished ability. 
U 
