4 CATALOGUE OF THE ZOorKVTE.S OP 



and palmated. At Bamborough I have obtained it five or six 

 inches in height and nearly as much in breadth. The largest 

 specimens appear to grow beyond low-water mark. 



Dr. Johnston has, I think, made a mistake in stating that 

 the papillae of this species are " each the cell of a polype." They 

 are imperforate, and much more numerous than the polype-cells, 

 which are disposed among them in the same manner as is repre- 

 sented in the figure of Cycloimi papillosum, given in " British 

 Zoophytes" (PI. Ixx., fig. 1). This figure has the appearance 

 of having been taken from a specimen of A. Mrsutum in its en- 

 crusting state. 



3. A. PARASiTicuM, Flem. 



Johns. Brit. Zooph., 362, t. IxrsHiii., f. 4, 5. 

 On Plumularia falcata and other zoophytes from deepish 

 water; common. 



4. A. MAMMILLATUM, 71. Sp. PI. VII., f. 3, 4. 



Encrusting, semitransparent, brownish, covered w4th rather 

 long, stout, and strongly wrinkled papillge, from which 

 the polypides issue : tentacles sixteen or eighteen. 



On old shells from deep water ; not uncommon. 

 Wlien carefully examined, this species can readily be dis- 

 tinguished from any of those previously described by the greater 

 size and elevation of the papillse, which, although varying much 

 in length according to their state of contraction, are always 

 sufficiently prominent to be easily recognised. When most 

 contracted, they appear lilte strong mammillge, but their more 

 usual form, when the polypide is withdrawn, is elongate-conical ; 

 when it is expanded, they are cylindrical and nearly linear. This 

 species is parasitical on old univalve shells from deep water, 

 which it envelopes with a subcoriaceous crust, never rising into a 

 free state. No septa are visible excepting in the margin of 

 young specimens, or when examined as a transparent object in 

 the microscope. 



5. A. ALBiDUM, n. sp. PI. VII., figs. 5, 6. 



