CRUSTACEA. 
5 
abruptly deflected for nearly an inch at the margins, and very indistinctly 
trilobate. 
Axis very broad, width more than two-thirds the width of the body. Seg¬ 
ments broad and flattened, abruptly deflected at the anterior and posterior 
margins and separated by very narrow transverse furrows, which are scarcely 
distinguishable for their entire length, but are most noticeable at the margins 
of the axis, where lie the deep depressions to the leg-bases or visceral 
supports. 
The deep transverse furrows along the middle of the segments are con¬ 
spicuous and most distinct toward the lateral margins of the thorax and upon 
the broad beveled articulating planes. The same liability to error in regard 
to the anterior and posterior limits of the segments is noticeable in the lower 
surface of this species as mentioned in the description of Homalonotus 
Dekayi. The segments are evenly curved over the axis and posteriorly 
deflected toward the margins^ 
Pygidium elongate-sub-triangular. Surface depressed-convex, sloping evenly to 
the margins. 
Axis well defined and composed of ten annulations, the articulating ring 
being the posterior half of the apparent last thoracic segment. These annu¬ 
lations are broad, flat or slightly rounded, and are nearly transverse, with a 
slight forward bend over the axis. 
The pleurae bear seven or eight distinct annulations. Posterior margin 
slightly produced. In one specimen the posterior extremity is broken away, 
its extension being indicated by the slope of the lateral margins, and in the 
other it has been displaced and forced to one side. 
Surface of the test characterized by tubules of comparatively small size, 
which have left their impressions on the cast of the lower surface. 
Observations. Of this remarkable species of Homalonotus but two examples 
have been discovered. The smaller of these, and somewhat better preserved 
specimen, showing the pygidium and five thoracic segments,. has served as 
the type of the original description, and the other which is here figured 
