382 
spots between the tentacles. The skin is closely and distinctly 
papillate, the papillæ being supported each by a group of hooks, 
generally 3—6 in each papilla (Fig. 62). When the skin is very 
much distended, the papillæ are in- 
distinct, but the arrangement of the 
sigmata in groups remains distinet 
enough. Sometimes, in the larger 
specimens, the hooks are very scarce 
in the anterior part of the body, the 
papillæ here having only one hook 
or none at all. Along the radii the 
hooks generally are more numerous 
and may form a close series, less 
distinctly arranged in groups, along 
each side of the radial muscle. Size 
of the hooks ca. O.os—0.i4 mm; 
their shape not especially characteristic. In the dorsal interradii 
numerous wheels are found scattered, in the Plimmerton specimens. 
In the larger specimens from Auckland Harbour and Stewart Island 
they are much more scarce; in one of them I have discovered 
only one single wheel, even abnormal in structure. The size of 
the wheels varies considerably, from 0.04 to O.i mm, samples of 
these various sizes being found especially among one another in 
the posterior end of the body in one of the Plimmerton specimens. 
The rim of the inner margin of the wheel with some 100 teeth, 
as in the wheels of Chiridota nigrå and carnleyensis from which 
they do not differ noticeably. The spicules of the tentacles bifid 
in the ends (Fig. 63.a). 
The calcareous ring not very solid, the pieces being easily split 
in hypochlorite of sodium. A distinet notch in the hind edge of 
each piece; radials imperforate (Fig. 59.a). 
The radial muscles with a distinet retractor- 
part, connected with the body wall through 
a membrane of connecting tissue, looking, 
in well extended specimens, like a sort of 
mesentery. Oesophagus rather short, without 
a muscular swelling. The alimentary canal 
straight, without any loop; it is somewhat 
a 1). 
Fig. 63. Spicules from ten¬ 
tacles of Trochodota Den- 
dyi (a) and Kolostoneura 
novæ-zealandiæ (b). 
