78 
donne lieu de croire que de nouvelles recherches et 
de nouvelles observations, prouveront qu’il n’est pas 
strictement vrai qu’en France, en Angleterre, en 
Russie, i/ n’exisie point de trilobites entiérement privés 
WUyeux, comme le dit le savant auteur que je viens 
de citer.’ See Annales des Sciences Naturelles, 
Vol. 8. page 195. | : 
Genus DipLeura. Green. 
Body, contractile, not much depressed, and slightly 
tapering. np at : é 
_ Buckler, pustulous, trilobate, cheeks protuberant, 
with oblique, annular, oculiferous tubercles. | 
Abdomen, with fourteen articulations, not lobate, 
the ribs double. | 3 
Tail, suborbicular, not so large as the buckler, co- 
vered with an epidermis. : , 
This genus derives its name from two Greek words, 
which signify double ribs; many of the trilobites are 
thus characterized; but in no species, is this organi- 
zation so remarkable as in those which belong to the 
Genus Dipleura. The expansion of the tail resem- 
bles, in some degree, that of the Isotelus, but other 
obvious characters sufficiently distinguish it from 
that interesting genus. The fossils arranged under 
this section are larger than most other trilobites. 
