The Echinoid Directory

Key to genera and subfamilies of Emiratiidae


1a. Ambulacral plating trigeminate throughout (one ambital plate per column may be quadrigeminate in some taxa). Go to 2	1b. Ambulacral plating consistently polygeminate (5 or more pore pairs to a plate) above the ambitus. Go to 4

2a. Ambulacra without obvious primary tubercles beneath ambitus. Colpotiara	2b. Large primary tubercles continue almost to the peristome edge in the ambulacra. Go to 3

3a. Peristome more or less flush, larger than apical disc; pore-pairs crowded towards peristome margin forming phyllodes. Polydiadema	3b. Peristome distinctly invaginated, smaller than apical disc; pore-pairs uniserial to peristome edge. Loriolia

4a. Ambulacral plating quinquegeminate throughout. Emiratiinae	4b. Ambulacral plating trigeminate orally, quadrigeminate to polygeminate above ambitus. Diplopodiinae