Prof. Allman on the Hydroid Zoophytes. 51 



tinous polypary is covered externally by the coenosarc, thus 

 reminding us of the sclerobasic corallum of some of the Ac- 

 tinozoa. 



In the present species the common basis of the colony con- 

 sists of an irregular network of chitinous tubes pervaded by the 

 coenosarc, and closely adherent to the surface of some fixed 

 object. I had long ago satisfied myself of the presence of a 

 basal tubular polypary in Clava; but, though I had carefully 

 figured it with a view to publication, I delayed making it 

 known, and in the meantime the same fact had been fully ob- 

 served and recorded by Dr. S. Wright. 



The medusa of Podocoryne alhida has a deep umbrella with 

 eight marginal tentacles, of which four are longer and continu- 

 ous with the four radiating canals, and four shorter and alter- 

 nate with them. Each tentacle springs from a bulbous base 

 containing red pigment-granules. There is also a wide velum. 



The manubrium is of moderate length ; and its oral end is 

 divided into four lobes, each of which is terminated by a cluster 

 of thread- cells, which are peculiar in the fact of every thread- 

 cell being borne on the summit of a delicate thread-like pe- 

 duncle. The entire cluster may be seen in a constant state of vi- 

 bration, — a phsenomenon, however, which is probably due merely 

 to the action of currents excited in the surrounding water by 

 cilia situated within the mouth. 



It is apparently the present zoophyte, or at least a nearly allied 

 species, which has been described by Mr. Peach in a former 

 volume of this Journal. 



III. Manicella fusca, nov. gen. et sp. 



There occurs in the Firth of Forth, attached to other zoophytes 

 and to sea-weeds near low-water spring tides, a Tubularian zoo- 

 phyte with characters so peculiar as to entitle it to a distinct 

 generic rank. 



It is much branched, rising usually to the height of about \ an 

 inch, and having its ultimate ramuli disposed with a regularly 

 pinnate arrangement. 



The tentacles are about 16 in number, arranged in a single 

 but slightly alternating series upon the club-shaped body, just 

 behind an anterior conical projection which bears the mouth on 

 its apex. 



The polypary, which is of a dull brown colour, and opaque 

 from the accumulation in it of minute particles of earthy matter 

 and siliceous sand, presents the remarkable character of not 

 being confined to the coenosarc, but being continued over the 

 body of the polype, and even for a considerable distance over the 

 tentacles themselves ; so that the onlv part of the zoophyte whicfa 



4* 



