72 
many striking generic distinctions. 
As far as I know them they must 
form at least 15 genera, and 4 series 
of beings, with many, two, one or no 
eyes. 
I. Series or Section. More than 
two eyes. Polyopsites. 
1. G. Alloctops, Raf. 1821. Tri- 
lobate not glomerate, head with 8 
unequal eyes in 2 longitudinal rows. 
Thorax and abdomen with many seg- 
ments. 1 . A .flexuola, Raf. about 20 
flexuose segments, fore eyes smaller, 
tail a little jutting obtuse. Cabinet 
of Transyl. University, from old 
limestone of Kentucky. 
2. G. Diplopsites, Raf. 1821. 
Not trilobate nor glomerate, head 
with 4 eyes double on each side. 
Thorax and abdomen with many seg- 
ments, l.D./ms.Very smooth, eyes 
equal. An imperfect specimen in the 
Cincinnati Museum, from Ohio. 
3. G. ToMOLiGus,Raf. 1821. Not 
trilobate but glomerate, head very 
broad, 2 large eyes cut in two 
lengthways. Thorax with few seg- 
ments, 4 or 5, abdomen large entire, 
Type. 1. T. mimulus , 1821, (or my 
trilobites simici,e num. 1831 .) Smooth 
2 furrows before each eye. Cabinet 
of Clifford, found in Salt River 
Knobs. 
II. Series or Sections. With two 
eyes. — DiopsriES,Raf. 
4. G. Isoctomesa, Raf. 1821. Iso- 
teles, De Kay, 1824. Nileus, Dolman, 
1826. Not trilobate nor glomerate. 
Head and abdomen large entire, 2 
distant eyes. Thorax with, 8 equal 
segments. Type 1 . T. emarginata. 
Eyes round, abdomen larger than 
the head, retuse or notched behind. 
Cabinet of Trans. University, pre- 
sented by Judge Bledsoe, found near 
Harrod’s Lick and Paris in Ken- 
tucky, in old limestone. The largest 
trilobite known, being 9 inches long 
and 4 broad. Different from the I. 
gigas of De Kay, which has bilobed 
eyes and is not notched. I.plana.1). 
and other sp. belong to this genus 
also. The G. Menus of Dolman, 
^rdly differs having only 9 or 10 
segments to thorax, it may form a 
sub-genus. 
5. G. Dipleura, Green, 1 832, Not 
trilobate, subglomerate, 2 oblique 
eyes, thorax with 14 segments, ab- 
domen or tail orbicular. See Green’s 
series No. 3. 
6. G. Asaphus, Br. 1822. Trilo- 
bate, not glomerate. Abdomen or 
tail expanded large, without seg- 
ments. Thorax with many seg- 
ments. Many sp. see Brongniart 
and Green. 
7. G.TRiLOBiTES.Park.l812. Glo~ 
merit es, Raf. 1817. Calymene , Br. 
1822, and Green, 1832. If the name 
trilobites is not to be generic, caly- 
mene must be changed nevertheless 
for diop sites or geoplaxis, Raf. many 
sp. I descr. 2 in my enum. T. eury - 
cephala and T. granulata . Green 
has 5 sp. in I. series, of which 3 news 
but his pretty C. calicephala ought to 
form a sub-genus Orimops , Raf. by 
eyes annular or with a central dot, 
and head with a furious relief like a 
flower de Luce. The G. differs 
chiefly from asaphus by having the 
abdomen with segments or blended 
with thorax, and both glomerate. 
8. G.TELESiops,Raf.l 832. Differs 
from the last, by head very broad, 
with remote lateral eyes, very large, 
prominent and reticulated. l.Type. 
T JeiocephasIRdti. Head smooth, eyes 
reticulated by dots, flat and smooth 
above, thorax with 11 segments, la- 
teral ribs duplicate, abdomen or tail 
with 7 segments flattened not dupli- 
cate. My cabinet, from Virginia, se- 
veral sp. blended under C. macroph - 
thalma of Br. must be united here, 
and probably also my T. eury cephala 
or Telesiops granulata . The T. , 
leiocephas I have ceded' to Prof. 
Green. 
9. G. PROMENiTEs,Raf.l832. Bi- 
lobites,Raf. 1821 and 1831, in enum. 
I have changed the name as there 
are several G. bilobites. 1. Pr. lunula 
Raf. 2. Pr. bilob ata, &c. 
10. G. Ogygia, Brongniart. 
III. Section or Series. Only one 
eye? Monopsites, Raf. 
11. G. Metapteles, Greeny or 
MoNOPSiTt’s, Gr. or Cryptolites, 
Gr. All these names proposed by 
