CATALOGUE OF ECHINIDA. 
41 
*** Subanal fasciole none. 
11. Faorina ; back nearly equal small tubercles. 
d. Lateral ambulacra similar , sunken ; lateral fasciole extending 
under the vent ; subanal fasciole none. 
12. Desoria; vertex anterior. 
13. Tripylus ; vertex central. 
14. Schizaster ; vertex posterior. 
e. Posterior lateral ambulacra petaloid , sunken ; anterior lateral , 
flat , elongate , like the anterior odd one , of only two rows of 
pores. 
15. Agassizia. 
Or the genera may be arranged and characterised thus : — 
I. Back with large , sunken , perforated tubercles. 
1. Lovenia; peripetalous fasciole none, subanal and internal 
distinct. 
2. Breynia; peripetalous, subanal, and internal fasciole dis- 
tinct. 
3. Spat angus; peripetalous fasciole none; subanal fasciole 
distinct. 
4. Kleinia ; internal fasciole none. 
5. Eupatagus ; peripetalous and subanal fasciole distinct ; in- 
ternal fasciole none ; ambulacra broad. 
6. Plagiostomus, peripetalous and subanal fasciole distinct; 
internal fasciole none ; ambulacra elongate. 
II. Back with nearly uniform small tubercles. 
* Ambulacra cruciform. 
7. Echinocardium ; peripetalous, internal, and subanal fasciole 
distinct, lateral none. 
** Ambulacra stellate , sunken. 
8. Brissus ; peripetalous and subanal fasciole distinct, internal 
and lateral none ; subanal disk very distinct, near vent. 
9. Brissiopsis ; peripetalous and subanal fasciole distinct, inter- 
nal and lateral none ; subanal disk distant from vent. 
e 2 
