134 
with a shining polished surface; it is filled with a gelatinous 
slime and covered with minute punctures. The polyp 0 
orifices are large, distant, and of very irregular shape. The 
polypes, though seen, in consequence of other engagement* 
were not examined till they had become too much injured 
for description. It varies in height to ten inches, and i® 
thickness to six. This I have failed to identify with anjj 
species described by the authors to whom I have access, and 
in fact is now held to be new. 
A. ECHINATUM. Encrusting, thin; surface granular 
when living, roughened with papillae when dead. 
A. echinaturn, Fleming’s Brit. An., p. 517. Johnston* 
Brit. Zooph., p. 304, pi. 42., fig. 3, 4. 
Hab. On dead specimens of the Buccinum undatum, and 
other dead univalve shells; common. Polperro, Mevagissey- 
Goran, and Whitsand bay. 
This species is invariably found encrusting dead univaB® 
shells, it is very thin, and of a brown colour. When living 
it is fleshy, slightly diaphanous, and the mouths of the cell* 
are but slightly prominent; when dry, it becomes liard» 
shrivelled, and the apertures of the cells prominent and still- 
The points or prickles, which are distributed over th® 
surface, have no permanent regularity, sometimes beinfe 
arranged in rows, as Dr. Johnston lias figured them, and a 
others distributed in a very irregular manner. 
Montagu first discovered it as a zoophyte, on the Devon- 
shire coast, and communicated it to Fleming; he says th® 
polypes have twelve lentaeula. 
A. PARASITICUM. Parasitical on corallines, arenaceous- 
cells distant, round, or substance porous. 
9 g 
A. parasiticum, Fleming’s Brit. An., p. 518. Johnston 
Brit. Zooph., p. 304, pi. II, figs. 4, 5. 
Dr. Fleming first placed this among the, zoophytes, but w ’ !1 ® 
apparently undecided to what genus it belonged, not lia'i [l tj 
an opportunity of examining it in a living stale. It is Ion” 1 
encrusting t he stems of the Serlutariadae , as S. abielii‘ a ’ 
and jiolyzonias, Flnmnlaria jalcala, %c. In appearance it * 
sandy, porous, and is about the tenth of an inch in tliickn®*'’ 
The cells externally, appear as minute distinct lubes, win® 
perforate the substance throughout. The, polypidom, in l;IL ’ 
instead of being secreted or formed by the animal as a I ,a | s 
of its own character, as the polypidoms of all the other*- 
formed of fine sand and mud, cemented together by a 
substance, as is observed in many worms, as in the Sabet 
fyc.j the whole appearance so closely approaches to wn® ^ 
observed in worms, that I am inclined to think it the work 
