J70 
CRUSTACEA. 
Trapezia, Lat. 
The Trapeziae resemble the Eriphise in the insertion of their lateral 
antennse, but their shell is nearly square, depressed, and smooth ; the 
eyes arc placed at its anterior angles, and the claws, in comparison 
with the other feet, very large. 
All the species are exotic and inhabit Eastern Seas. The 
PiLUMNus, Leach, 
Ditfers from the two preceding subgenera, in the insertion of the 
lateral antennse at the internal extremity of the ocular cavities, 
above the origin of the pedicles of the eyes. The Pilumni, as to the 
form of the shell, approach nearer to the Crustacea of the second 
section, than the other Quadrilatera, and in this respect stand some- 
what ambiguously between the two. As in most of the Arcuata the 
third joint of their foot-jaw is nearly square or pentagonal. The 
lateral antennse are longer than the ocular pedicles, and have a seta- 
ceous stem, longer than the peduncle, and composed of numerous 
small joints. The tarsi are simply pilose f. 
Thelphusa, Lat. 
The lateral atennse situated as in the Pilumni, but shorter than 
the ocular pedicles, composed of but few joints, and Avith a cylin- 
drico-conical stem, hardly longer than its peduncle. The shell is 
almost shaped like a truncated heart, and the tarsi are furnished with 
spinous or dentated ridges. 
Several species are knoAvn, all of which inhabit fresh water, 
but capable, as it would appear, of living at a distance from it 
for a considerable time. One of them, mentioned by the an 
cients, is found in the south of Europe, the Levant, and in 
Egypt; it is the Crabe jiuviatile, oi Belon, Rondelet, and Ges- 
ner§. It is very common in several brooks and various lakes 
of the craters of the south of Italy ; its effigy is observable on 
different antique Grecian medals, particularly on those of Sicily. 
The shell is about two inches in each diameter. It is greyish or 
yellowish, as the animal is living or dead, mostly smooth, with 
little incised rugae and asperities on the anterior sides. The 
front is transversal, inclined, reflected, and edentated. The 
claws are rough, with a reddish spot at the extremity of the 
fingers, which are long, conical, and unequally dentated. The 
Greek monks eat it I'aw, and during Lent it forms one of the 
articles of diet used by the Italians. 
* Cancer cyrnodoce, Herbst., b, 5 ; — C. rtifo-jnincfatus, Id., xlvii, 6 ; — C. glabcr- 
ritnns, Id., xx, 11.“). See the artiele Trapizie, Encyc. Methodique. 
-f- See the article Pilumne, Encyc. Method., and Desmarest, op. cit. p. 111. 
J The Pofamophiles of the first edition of this work. That name having been 
already applied to a genus of Coleopterous Insects, I have substituted the present 
one. — See this word in the second edition of the Nouv. Diet. d’Hist. Nat. They 
are the Pofamohite, Leach, Potanion, Savigny. 
§ See Olivier Voy., en Egypte, pi. xxx, 2 ; and the plates of Nat. Hist., in the 
creat work on that country. 
