298 



of digits. The wheel-papillae, which are said to be unusually large 

 in this species, are in the specimens at hand of very varying size. 

 While the smallest papillae are invisible to the unarmed eye and 

 do not enclose more than 4 — 6 wheels, the largest papillae measure 

 up to 2,3 mm in diameter and include more than 300 wheels. The 

 wheels measure 70 — 130 pb in diameter. The wheel-papillae are 

 arranged in a single row in each interradius, and densest in the 

 three dorsal ones. 



The calcareous ring (Fig. 62. 1) consists of 12 pieces, the four of 

 which are perforated for the passage of the nerves. The midventral 

 radial differs from the others in being notched in the anterior margin. 

 A cartilaginous ring is wanting. There are seven polian vesicles 

 and a single stone-canal. The madreporite (Fig. 62. 6-7) is rather 

 short and has some few large folds. It differs from the madreporite 

 in the other species examined in the calcification being not con- 

 fined to the exterior side of it, but equally developed around the 

 end of the stone-canal. The sexes are separate and the gonads are 

 much branched. The genital duct opens on a little papilla close 

 behind the dorsal tentacles. The alimentary canal has a large loop 

 and the ciliated funnels are found at the base of the mesenteries. 

 Ludwig writes that "das Mesenterium des absteigenden Darm- 

 abschnittes trägt keine Wimperbecker". This does not agree with 

 the specimens at hand, which have ciliated funnels on all three 

 mesenteries. The ciliated funnels (Fig. 62. 2) measure from 1 50 ^ 

 to 350 jit and are more or less regularly funnel-shaped. They have a 

 short stalk, but are not united into clusters. Among the funnels there 

 are found some 50 — 70 ^ large, long-stalked bodies, which are very 

 like small ciliated funnels. Whether they really are ciliated funnels 

 or not, it is not possible to decide on the material at hand. 



Besides the wheels there are no calcareous deposits in the skin, 

 but in the longitudinal muscles there are, as mentioned by Lud- 

 wig in 1898, numerous oblong bodies. These latter are in the 

 posterior end of body very regular (Fig. 62. 3), but in the anterior 

 end of body they are of a somewhat varying shape (Fig. 62. 4) with 

 a more or less undulating outline. The rods in the digits (Fig. 62. 8) 

 are exceedingly characteristic, the one end being as a rule more 

 sharply curved than the other. These rods differ from those in the 

 tentacle-stem (Fig. 62. 9), which are more or less irregularly shaped. 



