156 BULLETIN OF THE 
Family CORYSTIDZ. 
TRACHYCARCINDUS, gen. nov. 
Carapace pentagonal, moderately convex, lateral margins long, nearly straight 
toothed. Front narrow, produced, three-toothed. Orbits large, with forward 
aspect, imperfect, with two hiatuses above, one below, and one at the inner 
angle; lower wall formed chiefly by the carapace. Anterior margin of buccal 
cavity not distinctly defined, epistome short, ridges of the endostome devel- 
oped. Sternum long and rather narrow. Abdomen of male narrow and five- 
jointed, the third, fourth, and fifth segments consolidated. Eyestalks very 
small, retractile within the orbits. Antennules longitudinally folded. The 
antennee lie in the inner hiatus of the orbit; their basal segment is but 
slightly enlarged, not filling the hiatus at the inner angle of the orbit, nor 
attaining to the front, subcylindrical, unarmed, imperfectly fused with the 
carapace ; the second segment is longer and slenderer than the first, the third 
segment about equal to the second in length, but slenderer ; all these segments 
are furnished with long and coarse setz ; the whole antenna is less than one 
half as long as the carapace. The ischium of the outer maxillipeds is produced 
at its antero-internal angle ; the merus of the same appendages is rounded at 
the antero-external angle, obliquely truncated but not emarginated at the 
antero-internal angle, where it articulates with the following segment. Legs 
of moderate length. Right and left chelipeds very unequally developed in the 
male. Dactyli of ambulatory legs styliform, straight, slender, longer than the 
penultimate segments. 
The pentagonal shape of the carapace recalls the genus Telmessus White. 
But in T’elmessus the front is divided by a median notch, the orbit is much 
more complete, the basal segment of the antenna sending off an external pro- 
cess that completely fills the hiatus at the inner angle of the orbit. In the 
structure of the orbit and antenne, and in the shape of the merus of the outer 
maxillipeds, Trachycarcinus is much like Hypopeltariwm Miers (Peltarion 
Jacq.)- 
Trachycarcinus corallinus, sp. nov. 
Carapace irregularly pentagonal, clothed with a dark brown pubescence, and 
bearing flattened tubercules of ivory whiteness arranged in groups, as follows: 
two anterior lateral and one posterior median, on the gastric region; four, dis- 
posed in two pairs, on the cardiac region; five or six on each branchial region; 
and one, of a crescentic shape, on each hepatic region. Each group of tubercles 
resembles the crown of a complex molar tooth whose cusps have been worn 
down to a common level. Front tridentate, the median tooth twice as long as 
the lateral. Walls of the orbit furnished with four teeth separated by deep 
hiatuses ; these teeth are a pre-ocular, median superior, post-ocular, and sub- 
