VI 



New Types. 



Studeriotes is an Alcyoniid or a Ne})hthyi(l of very remarkable structure 

 perhaps with distant affinities with Paralciioniimi. It consists of a strong 

 densely spiculose cup, within which very numerous finger-like polyp-bearing 

 lobes or branches are retracted ; these arise at different levels from a strong 

 muscular central thalamus, and from the upper parts of the inner wall of the 

 cup ; each finger-like lobe is thickly covered with polyps and ends in one larger 

 than the rest ; the cavities of the polyps communicate with a central canal in 

 the digitiform lobe, and these central canals unite in a few large longitudinal 

 canals with large muscles on their walls and with few spicules ; the polyps 

 have a distinct non-retractile calyx covered with spindles arranged in double 

 rows ; the spicules are all warty spindles, except a few minute irregular forms 

 found (along with sparse spindles) in the canal walls ; many of tlie cortical 

 sjiindles attain huge dimensions, some exceeding nine millimetres. In many 

 respects this is a divergent form, highly differentiated in the direction of 

 retractility of polyparium. 



The genus Cacto(jonii<i, defined in a separate publication, seems referable 

 to a position in the sub-family Siphonogorgiiue. It differs from the Si/'ho/zo- 

 g()r(/ia-ty\)e in being even more densely spiculose and rigid, in showing a marked 

 division into trunk and polyp-bearing portion, and in the absence of definite 

 branching, the polyps being borne mainly on the margin of Hattened lobes. 

 The mode of growtli is Cactus-like ; the anthocodia^ have a dense armature of 

 " crown and points," and arc completely retractile within distinct verrucas ; the 

 tentacles are simply infolded. The sjjicules of the stem and trunk are thick, 

 warty spindles ; those of the crown and points are spindles or clubs ; those on 

 the aboral surface of the tentacles are small, fiat and scale-like. 



The genus JJactylonephtliiia seems to occupy an intermediate position be- 



