CRUSTACEA. 
89 
P R O E T I D ^. 
PROETUS, Steininger. 1831. 
Proetus Conradi. 
PLATE XX. PIG. 9. PLATE XXI, FIGS. 27, 28; AND PLATE XXII, FIG. 4. 
Proetus Conradi, Hat.l. Descr. New Species of Fossils, etc., p. 69. 1861. 
Proetus Covradi, Hall. Fifteenth Rept. N. Y. State Cah. Nat. Hist., p. 97. 1862. 
Proetus Conradi, Hall. Illustrations of Devonian Fossils, i^l. xx, fig. 6 (not figs. 5, 8, 9). 1876. 
Proetus marginalis. Hall. Illustrations of Devonian Fossils, pi. xxi, figs. 27, 28. 1876. 
General Form and Proportions. Outline elliptical or sub-ovate; length to 
width as 3 to 2. 
Surface convex; depressed or flattened near the longitudinal furrows. 
Cephalon semi-elliptical; length to width as 1 to 2. Border very broad, gently 
convex toward its inner edge, sloping evenly outward and at the outer edge 
faintly reflexed; at the genal extremities produced into short, stout spines, 
extending as far as the fourth thoracic segment. 
Facial Sutures normal, crossing the anterior border more directly than in 
Proetus angustifrons. 
Glabella short, slightly longer than wide ; sub-ovoid; tangent at its anterior 
extremity to the inner margin of the border. Surface depressed-convex, 
slightly flattened above. Casts of the lower surface show well-defined 
basal lobes, and under favorable preservation the other glabellar lobes would 
probably be apparent. Occipital furrow deep; occipital ring moderately 
broad and elevated; occipital lobes inconspicuous on the dorsal surface, but 
quite large in the internal cast. 
Cheeks narrow, broadly flattened about the eyes, and abruptly deflected to 
the marginal sulcus. The most elevated portion of the cheeks lies in the 
angle made by the marginal sulcus and occipital furrow. 
