17 
Genus Fifth.  Aewosrus. 
Body edad sae icalindticas 
~ Buckler and flanks ed et edges being lightly 
elevated. | 
Middle lobe with two transverse divisions, ancwe com- — 
posed of a single piece. as 
Two glandular tubercles on the anterior part of the — 
body. | 
In 1824, Dr. J. E. Dekay added a sixth genus to 
the family of the tr ilobites, which he describes in the 
following manner. | | 
Genus Sixth. isore.vs. 
Body oval oblong, often a not unfrequent- 
ly extended. 
Head or buckler large and rounded, equaline the — 
tail in size, with but two oculiform tubercles. 
Abdomen with 8 articulations. 
Frontal process beneath, with two hitomi! ter- 
minations. ; 
Post-abdomen or tail broad, expanded with indis- 
tinct divisions, as large as the buckler. 
Longitudinal lobes very distinct. ieee ie 
This genus, he remarks, will be sufficiently distin- 
euished from the five genera proposed by M. Alexan- 
dre igniart in his valuable and truly philoso- — 
phical work on the trilobites by the following parti- | 
culars. 
From Culymene. By the presence of but two tu- 
B 2. 
