84 
THE SCIENTIST. 
tapering, wiib margins rounding to pos 
thrior extremity. 
Cjpliilon broad, semi-elliptical, being 
sljo-litly flattened eaeh side of the j;la- 
bella ; widtli twice tile length, straight 
behind, with posterior lateral angles, ter- 
minating in long pointed, spine-like ap- 
pendages, extending back to the last 
thoracic segment, and sometimes to the 
second axal segment of the pygidinm. 
Glabella, sub-ovoid, with greatest con- 
vexity abont center of the palpebral lobe 
slightly constricted in front of eyes, and 
somewhat abruptly rounded in front .; 
width, opposite center of eyes, equal to 
length; a distinct furi'ow separates ii from 
tlie cheek, and passes around to the 
fro)it. 
The basal or posterior lateral lobes 
.are sub-pyiiform in, outlijie. and^^aie 
isolated by a well defined furrow, pass- 
ing from near the center of the palpe- 
bral lobe, obliquely across, with a back- 
ward curve, to the occipital or neck 
fan*ow, each of . which ]-each about one- 
third tiie' distance across the base of ihe 
Glabella. 
" The second and third lateral furrows 
frdlii.tiie. base are nearly parallel with the 
iirst, and extend about one third way 
across on each side, and are less distinct; 
the fourth lateral furrows are very faint 
and short, often not noticeable without 
a glass. 
The occipital segment is \ve]\ defined, 
lower, and considerably shorter in its 
transverse diameter than the. glabella; 
strongly arched across, and projecting 
slightly back of the line of the cheeks. 
Cheeks broadly marginate; com 
pared with glab.ella and eyes, medi- 
um; sloping abruptly from the eyes into 
broad marginal furrows, which become 
obsolete on reaching the anterior lateral 
margin of the glabella, and dividing 
below the center of the eyes into two 
shallow furrows, the outer extending 
backwards almost to the md of the-long 
posterior lateral spine-like appendages., 
while the iimer furrow continues around 
and under the eyes to ' the vporiterior 
margin. The posterior tnai-gins elevated 
forming a rim,*;which is well detiJied by 
deep . fuiDws, coresponding in line tO; 
the ngck or occipital furrow, "and con-I 
tiiuiing backward, and uniting with the 
lateral marginal furrows. The • paits 
sloping from the eyes to the broad mar- 
ginal fui-rows are beautifully maiked 
with radiating stria and punctures, ex- 
tending downward from the entire under 
side of the eye, and almost "crossing the 
I n a rg i ij a 1 a n d la te r al f u r r o Wb . 
Eyes lunate, sub-reniform, modei'ately 
large, being about five-twelfths the 
length of the glabella, prominent, though, 
notas high as the glabella, located about 
onelialf their. own length in front of the 
posterior margin of the cheeks. Visual 
surface smooth and apparently polished, 
semi-transparent, glrowing faint outl i nes 
of the lenses beneath, when examined 
with a magnifying .glass. On removing 
this semi-transp;ii-ent crust .which readi- 
ly scales ofi'. we find a finely marked com- 
pound eye (see Fig. 2. PJate 1. which is 
magnified sixty-four times from Fig la.) 
Each eye has fort.7-eight diagonal rows 
the central rows are composed of twenty 
hexagonal lenses. 
The palpebral lobes, which rest on the 
eyes like lids, are separated from the gla- 
bella by a sharplj^ ddflned furrow, the 
lateral edges rounding abruptly to the 
eyes and haying a row , of longitudinal 
: depressions, parallel to the upper lines of 
the eyes (see enlarged.figure .of the eye). 
Thorax about same length ^is cephalon. 
and somewhat narrower, distinctly trilo- 
bate; segments nine, mesial lobe promi- 
nent and arched.- Lateral lobes flat to 
the knee angle of each segment, which is 
about the middle, thence sloping abruptly 
to the margin. Pygidinm elongate, near- 
