73 
little from those above noticed, these are also with- 
out names. Under such circumstances, we have 
thought it expedient to group these relics under 
the generic term of Cryptolithus, a name analogous 
to Calymene, Asaphus, Ogygia, and Agnostus, and 
which may with propriety be applied to the animal, 
should it ever be discovered entire.* | 
Body, contractile. 
| Buckler, lunate, convex, outer edge surrounded by 
a eesicieee lei reticulated, or tessellated border. 
Front or middle lobe of the buckler very protube- 
rant. ! 
Oculiferous protuberances, none. 
Abdomen, much compressed, tr slic: 
Cryprotiruyus Tesserztarus. Green. Cast No. 28, 
and Fig. A. 7 is ee 
Clypeo rotundato, fronte valde convexo, capite an- 
tice semicirculari margine tessellato ornato. 
Outline of the buckler hemispherical, the edge sur- 
rounded by a semicircular border of tessellated or 
rounded punctures, in three concentric rows in front 
—on each side near the posterior angle of the buck- 
ler, these rows of punctures are more numerous; 
the front is highly convex; is rounded before, and 
* Since the above was written, and the C. Tessellatus pub- 
lished, I have received a fine specimen of this trilobite from Pro- 
fessor Eaton, in an almost perfect state, so that the entire ani- 
mal can now be described. 
G 
