534 Miss H. D. Currie—Fossils from Western Persia. 
in the posterior pair by one, two, three, or four pairs, according 
to the height of the individual, the higher individual having the 
greater difference. In a few specimens, however, the number of 
pore-pairs in the anterior and posterior ambulacral areas is the 
same. The space between the pore zones is very narrow and in 
a groove; its width is a little less than the length of the larger 
pore. 
Interambulacral areas——One plate corresponds to seven in the 
ambulacral area. Hight plates in a column can be counted above 
the ambitus. The tubercles, which are distributed unevenly over 
the areas, are largest and show rough alignment on the adambulacral 
parts. The intertubercular spaces are covered with small granules 
which form scrobicules round the tubercles (Fig. 6.) The number 
of tubercles increases towards the ambitus, and on the inferior surface 
they are very numerous and close together, except in the areas 
corresponding to the posterior ambulacra which are devoid of 
tubercles. 
; 29 00° 
99 oF 0 2 a0 
(oe) 00%90 9900020 
(2) 
00-0009 
9 600a000°° 
oo 
09 
Fic. 6.—Arrangement of tubercles, magnified about twelve times, and showing 
areas where tubercles have been knocked off. 
Dimensions —The following are the dimensions of the specimens 
given as types in Figs. 1-4 :— 
LENGTH. BREADTH. HEIGHT. 
mm. mm. mm. 
39 37 29° 
29 26 18) 
29°5 28°5 19°5 
36 32 22°95 
The dimensions and the shape of these specimens seem very 
divergent for one species, but as they are exactly similar in other 
respects it is best to regard them as different varieties of the species. 
