351 
skin, the other end protruding; these protruding ends, which are 
finely spinulose, overlap, and these are the scales to be seen in 
the skin which produce the scaly appearance distinet even to the 
naked eye. Furthermore the arrangement of these scales is fairly 
regular, transverse to the longitudinal axis of the body, and thus 
Fig. 34. Fig. 35. 
Fig. 34. Part of skin of Caeumaria Huttoni, showing the large, saddle-shaped plates 
and the small buttons. Fig. 35. Buttons of Ciic. Huttoni. ™/i. 
that from the ventral midline they imbricate towards the dorsal 
side, meeting from the two sides in the dorsal midline. This ar¬ 
rangement becomes less distinet towards the ends of the body, and 
at the tail end they all imbricate caudad. Between these larger 
scales the skin is filled up by a great number of small, oval or 
round plates of the structure described by Den dy and Perri er, 
measuring ca. O.i— O.3 mm in greatest diameter. The holes in them 
are few and small and may entirely obliterate, leaving only fine 
concentric lines, the plates representing then small, glassy buttons 
(Fig. 35). Also along the edges fine concentric lines are often seen. 
The introvert is entirely without calcareous deposits. The tube- 
feet are, as stated by Ludwig, entirely devoid of calcareous de¬ 
posits, excepting the small terminal disk. The tentacles contain ir- 
