106 ALDER, ON NEW BRITISH POLYZOA, 
consisting of a single layer, assuming the form of a hollow 
cylinder, with the edges slightly appressed at their junction. 
Mr. Hincks has also met with similar examples. It is rather 
singular that on this coast, where for the first time the spe- 
cies has been found in its perfect state, the Lepralian or rudi- 
mentary form is unknown. In its intermediate state this 
species has all the characters of the genus Hemeschara of 
Busk. At present, I am inclined to consider that genus as 
only a peculiar state of an Eschara, and which some species 
have more tendency to assume than others. 
E. Landsbovorii differs from most of the other members of 
the genus, in having the two layers of cells readily separable 
—a character that has been considered generic by some 
authors, but which does not appear to be of any great im- 
portance. 
EscHARA PAVONELLA, Alder. 
Polyzoary foliaceous, yellowish, forming continuous flabel- 
liform or undulating expansions, arising from an encrusting or 
clasping base. Cells oval or oblong, with large perforations 
generally radiating from the centre to the circumference. 
Apertures orbicular, large, with a thin, plain margin, and a 
small mucro below, having a flattened and truncated apex. An 
oval avicularium on each side of the mouth. No ovicells have 
been observed. Height, about an inch and a half; breadth 
variable, but generally exceeding the height. 
E. cribraria, Busk, in ‘ Journ. Micros. Soc.,’ v. iv, p. 31], 
t. 10/1687; 9: 
Excellent figures of this beautiful species were given by 
Mr. Busk in the ‘ Microscopical Journal,’ from specimens I 
had the pleasure of sending him from Newcastle a few years 
ago. That gentleman then considered it to he the E. cribra- 
ria of Johnston, an opinion which now proves to be erroneous. 
I was first led to this conclusion from observing that Dr. 
Johnston mentions, in his account of E. cribraria,* having 
had a fragment of another native species sent him from Scar- 
borough, by Mr. Bean, but too imperfect for description in 
so difficult a genus. Mr. Bean has favoured me with a sight 
of this fragment, which proves to belong to the present spe- 
cies, aud which Dr. Johnston, therefore, evidently considered 
distinct from his E. cribraria. An examination of Dr. John- 
ston’s specimen of the latter species in the British Museum, 
sah made for me by Mr. Norman, confirms this opinion, 
* ‘British Zoophytes,’ 2nd Ed., p. 353, 
