from the Island of Malta. 71 
from each other: the thinness of the border and flatness of the 
dorsal surface are diagnostic characters by which it may be 
known from its congeners. 
Locality and stratigraphical position.—The only specimen we 
know from Malta is that contained in Earl Ducie’s collection ; 
it was obtained from bed No. 2. We have another specimen 
before us, kindly sent by M. Michelin from the Miocene terrain 
of Balistro, in the Gulf of Santa Manza, Corsica. Agassiz and 
Desor, on the authority of M. Deluc, give the tertiary of Palermo 
_ as the locality of their specimen. 
History.—This species is enumerated in the ‘ Cat. rais.’ of 
Agassiz and Desor, and stated to be “ espéce trés plate, 4 bords 
tranchant.”’ A detailed description of this interesting form is 
now given for the first time. 
. Genus Scureiya (Lamarck, 1816). 
Form in general suborbicular, extremely depressed, almost 
always discoidal, more or less enlarged behind ; border often tren- 
chant, disc entire, margin lobed; posterior border truncated; upper 
surface slightly convex; ambulacral flower small, with elegant, 
flat, blunt leaves; poriferous zones forming nearly a closed 
arch around them at their base; genital pores four, set around 
. the spongy madreporiform body; base flat; mouth small, 
central, and pentagonal, with five ramose ambulacral furrows, 
sometimes branched, passing from the mouth to the border : 
tubercles microscopically small and very numerous; test thick, 
interior divided by pillar-like processes: auricles five; jaws 
forming a more or less elevated star composed of five distinct 
pieces, each formed by the organic union of two elements ; teeth 
five, linear, and horizontal. This genus, as now limited, con- 
tains only fossil species, one of which is from the chalk of 
Georgia, United States; all the others are from the tertiary 
rocks. 
Scutella subrotunda, Leske. 
Syn. Echinus Melitensis, Scilla, De Corp. Marin. tab. 8. figs. 1-3. 
Echinodiscus subrotundus, Leske apud Klein, tab. 47. fig. 7. p. 206. 
Echinus subrotundus, Gmelin, Linné by Turton, vol. iv. p. 152. 
Scutella subrotunda, Lamarck, Animaux sans Vert. 2nd ed. tom. iii. 
p- 284; Defrance, Dict. Se. Nat. tom. xlvin. p. 230; Des- 
moulins, Etudes des Echinides, no. 24. p. 232; Grateloup, 
Ours. Foss. pl. 1. fig. 1. p. 36 ; Agassiz and Desor’s Cat. rais., 
Ann. Se. Nat. tom. vii. p. 132. 
Test very flat, suborbicular; dorsal surface slightly convex ; 
ambulacral areas exceeding in length the semi-diameter of the 
VOL, Il. G 
