116 Dr. T. Wright on Fossil Echinoderms 
& Boutonnet prés de Montpellier, et en Italie dans les couches, 
qui paroissent appartenir au calcaire coquillier grossier*.” 
EXPLANATION OF PLATES IV. V. VI. ann VII. 
Puate IV. 
Fig. 1. Cidaris Melitensis: a, the upper surface; 6, side view of the am- 
bulacral and interambulacral areas, natural size; c, an interam- 
bulacral plate, and a portion of an ambulacral area with the 
poriferous zones, magnified. 
Fig. 2. Echinus Duciei: a, upper surface ; b, side view, natural size ; c, the 
form of the mouth-opening, showing the disposition of the mar- 
ginal notches ; d, the five jaws and teeth “in situ,” imbedded in 
a mass of rock; e, the apical disc, showing the arrangement of 
the genital and ocular plates; jf, two interambulacral-plates, and 
a portion of a poriferous zone, magnified. 
Fig. 3. Echinolampas Deshayesti: a, the upper surface; 6, the under sur- 
face, natural size; c, a portion of the test, showing the tubercles, 
magnified ; d,a portion of an ambulacral area, and poriferous 
zones, magnified. 
PLATE V. 
Fig. 1. Brissus latus: a, the dorsal surface, reduced one-third in size ; 
b, the apical disc, magnified; c, the perforated tubercles, with 
their crenulated bosses and encircling granules, magnified. 
Fig. 2. Brissus oblongus: a, the upper surface, showing the petaloid am- 
bulacral star and peripetal fasciole ; 6, the under surface, showing 
the subanal fasciole, natural size ; mouth, and the ¢rajet of the 
naked basal portions of the ambulacra; c, the tubercles, and 
their circles of granules, magnified. 
Fig. 3. Schizaster Parkinsoni: a, the upper surface, showing the petaloid 
ambulacral star, the peripetal and lateral fascioles, the natural 
size; 6, a portion of the peripetal fasciole, with the boundary 
granules, magnified; c¢, a portion of the poriferous zones, mag- 
ified. 
Puate VI. 
Fig. 1. Brissopsis Duciei : a, the upper surface, showing the petaloidal 
ambulacral star, surrounded by the peripetal fasciole, reduced 
one-third; 6, six plates with small poriferous tubercles from the 
anteal sulcus ; c, form of the pores, and arrangement of the tuber- 
cles in the poriferous zones; d, the larger perforated tubercles, 
and their crenulated bosses with their circlets of granules ; e, a 
portion of the peripetal fasciole, showing how distinctly it is 
defined from the rest of the surface by rows of granules. 
Fig. 2. Brissopsis crescenticus : a, the upper surface ; 6, the under surface, 
natural size; c, the arrangement of the pores, near the apical 
portion of one of the zones. 
Fig. 3. Schizaster Desori: a, the upper surface; b, the under surface, 
natural size; c, the perforated tubercles, with their circlets of 
granules and crenulated bosses, magnified. 
* Dict. Sc. Nat. tome xxv. p. 453, 
