62 MR. ALDER ON NEW P0LYZ0A. 



peculiar state of an Eschara, and which some species have more 

 tendency to assume than others. 



E. Landsborovii 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 importance. 



Mr. Embleton has kindly presented his unique specimen to the 

 Newcastle Museum. 



Eschara pavonella, Alder. 



Polyzoary foliaceous, yellowish, forming continuous fialeliform 

 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 orbi- 

 cular, large, with a thin plain margin, and a small mucro below, 

 having a flattened and truncated apex. An ovalavicularium on 

 each side of the mouth. No ovicells have been observed. Height 

 about an inch and a half; breadth variable, but generally exceed- 

 ing the height. 



E. crilraria, Busk, in Jour. Micros. Sc, vol. IY, p. 311, 

 T. 10, figs. 7, 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 be the E. crihraria 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. crihraria,* having had a fragment of another 

 native species sent him from Scarborough 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 species, and which Dr. Johnston therefore evidently 

 considered distinct from his E. cribraria. An examination of Dr. 

 Johnston's specimen of the latter species in the British Museum, 

 lately made for me by Mr. Norman, confirms this opinion, and 



* "British Zoophytes," 2ml Ed., p. 353. 



