ARTHROPODA 
CRUSTACEA. 
BRACHYURA 
Indeterminate Crustacean. 
PI. XIII, fig. 1. 
There is, in my collection, a specimen of the great chela of a 
crustacean, possibly Paramithrax, but it is so poorly preserved 
that its determination is very doubtful. 
Locality. — Shoal Creek, Austin, Texas. 
Genus GRAPTOCARCINUS. 
Graptocarcinus texan us Roemer. 
PI. XIII, figs. 2, 3. 
Graptocarcinus texanus Roemer, 1887, Neues Jahrbuch f. Min- 
eral. und Paleont. Band 1, Heft. 2, pp. 173-176, figs. 
a and b, text. 
Dimensions. — Length, 28mm.; breadth, 36mm. 
Description , original somewhat modified. — Cephalothorax 
transverse oval, rounded, five-sided in outline; enclosed by a 
fine, raised, sharp border separating the dorsal and ventral sur- 
faces; dorsal surface moderately convex, flattened centrally; 
frontal bent downwards, ending in a broad, obtuse-angled, 
pointed rostrum, divided medially by a fine, longitudinal fur- 
row; outer margin of rostrum raised; orbits deeply cut. Sur- 
face coarsely and thickly granulate; between the grains or tu- 
bercles are scattered separate smaller ones. Where the tubercles 
are not completely preserved and crumbled on the summits, 
they appear ring-like and deepened in the centre. On the cen- 
tral surface are two pairs of converging furrows. The furrows 
of the anterior pair are longer and stronger than those of the 
posterior. They are bent slightly inwards and converge at an 
angle of about 130°. They are deepest and broadest at their 
outer ends. At their inner ends, they are so weak that their 
junction is scarcely visible. The furrows of the posterior pair 
