172] 
RECORDS OF W.A. MUSEUM. 
pedicels rapidly, almost abruptly decrease to only four or three and 
then disappear altogether, so that there are no pedicels near either 
mouth or anus, even in the ventral ambulacra. Dorsal ambulacra 
(except to some extent near mouth) and all interambulacral areas, 
entirely free from pedicels or appendages of any kind. Body wall 
thick (in the type which has been preserved in alcohol, it is 2-3 mm 
thick) but entirely without calcareous deposits of any kind ; a few 
minute calcareous rods are to be found in the finer branches of the 
tentacles, and the anus is guarded by five conspicuous calcareous 
teeth. Interambulacral areas somewhat pointed and projecting at 
both their anterior and posterior ends, forming valve-like folds 
which, in the contracted condition, conceal both mouth and anus. 
Colour rose-purple, dull in the type and passing into brown on 
the tentacles, but rather bright in the other specimen, which might 
perhaps better be described as purplish-rose ; in this specimen the 
tentacles are fully contracted and drawn into the body cavity and 
the neck-skin thus protected is bright purple, which is perhaps the 
natural colour of the entire animal in life. 
The form of this species is notable and is better shown in the 
type, which is approximately 90 mm. long. The distance from 
mouth to anus along the mid-dorsal interambulacrum is however 
less than 70 mm. while along the mid-ventral ambulacrum it is 
210 mm. The girth of the body is 190 mm. 
Port Hedland, W.A. Two specimens, Nos. 4032 and 4033. 
No. 4033 is the Type. 
It is difficult to decide whether the absence of calcareous 
particles in the body-wall is the natural condition or is due to 
decalcification. The type is so well preserved it is hard to believe 
it has been decalcified, but the other specimen was preserved in 
formalin and has the appearance of having been decalcified. If 
decalcification has occurred artifically it is hard to understand why 
the anal teeth and calcareous ring should persist apparently unin- 
jured. On the other hand, the species of Colochirus, hitherto 
known, have an excessive amount of calcareous matter in the body- 
wall and its absence would therefore be an extraordinary specific 
character, should it prove to be natural and constant. The form of 
the body in these two specimens and the absence of pedicels on the 
dorsal surface are also extraordinary characters and should further 
