Table 1. Environmental distribution of lists.

	Environment
Time interval	Basin	Offshore	Deep subtidal	Shallow subtidal	Peritidal	Reefs	Undefined
Wenlock	1	50	23	10	18	10
Telychian	10	18	27	29	1	3	18
Aeronian	0	38	7	25	1		1
Rhuddanian	2	15	23	5	2		16
Ashgill	1	33	21	31	2		22
Upper Caradoc	4	54	43	48	3		7
Lower Caradoc	4	62	35	17	4		2

Numbers designate the number of lists entered for each environment in each time interval.