165 
few remarks need to be added; but figures and measurements, which 
have not hitherto been given, are to be supplied here. 
Diameter. 
mm 
Height. 
mm 
system. 
mm 
Periproct. 
m m 
Peristome. Amb. plates. 
mm 
I.amb. plates. 
Spines. 
mm 
56 
42 
13 
6,5 
16,5 
35 
24—25 
10 
50 
36 
12 
6 
13,5 
36-37 
26—27 
— 
50 
38 
12 
6 
15 
27—28 
20 
— 
49 
35 
12 
6 
13 
33 
26 
6 
40 
30 
9 
4,5 
13 
30—31 
22 
6 
39 
27 
9 
4,5 
14 
27-28 
21 
9 
31 
21 
7 
4 
12 
27-28 
23 
— 
As 
seen by these 
measurements, 
there is a 
considerable 
vari- 
ation in 
shape 
as well 
as in 
the number of plates, as exemplified 
to a striking 
degree 
by the 
two specimens of 
50 mm h. 
d. — 
When, moreover, the colour is different, one having the character- 
istic pink tubercles with a slight greenish and pinkish tint on the 
middle of the plates, the other being perfectly white on test, tub¬ 
ercles and spines, one would be inclined to think them to be two 
distinet species. But as there are all transitional forms, and espec- 
ially the very characteristic arrangement of the tubercles being 
the same, it must be conceded that they belong to the same spec¬ 
ies, which is, however, somewhat more than usually variable. 
Concerning the tuberculation, attention may be called to the 
rather conspicuous feature that on the oral side the confluent are- 
oles of the tubercles in the same transverse row produce slightly 
elevated, vertical, separating walls. In the ambulacra also such 
horizontal walls are found, while in the interambulacra the trans¬ 
verse series of the consecutive plates are far from one another 
and separated by miliary tubercles, excepting only two or three of 
the lowermost plates. “Crenulation“ as that seen in albocinctus 
is not observed. 
The peristome is rather variable in size: it is perfectly naked, 
excepting the buccal plates which are covered with a dense coat 
of ophicephalous pedicellariæ with a few triphyllous ones among 
them. 
The apical system (Fig. 10) is rather naked, sometimes distinetly 
elevated; the genital plates generally carry only three larger tub¬ 
ercles, close to the inner edge, and a very few miliary tubercles. 
Ocular I is generally broadly insert; in one case, in an otherwise 
