CRUSTACEA. 
1] 3 
Genus Xantho, (Leach.) 
The following species of Xantiio seems to have 
a close analogy to several others already described, 
without well agreeing with any of them ; indeed, 
the descriptions heretofore given by authors of se- 
veral species of this genus, are too brief, when con- 
sidered as applying to a group so extensive, so 
widely diffused, and composed of individuals nearly 
related to one another. 
X. intonsus. Mus. Acad. 
Testa polita, nodosa, leviter convexa, margine utrinque 
4-dentata: fronte producta, inequaliter 4-lobata ; pedibus 
compressis, valde ciliatis ; manibus supra cristatis, externe 
carinatis. 
Shell polished, not greatly convex, anteriorly and 
antero-laterally divided by broad, shallow, some- 
what interrupted grooves, into several great, but 
little elevated lobes, thinly besprinkled with large, 
unequal punctures, very visible through a micro- 
scope ; antero-lateral margin with four teeth on 
each side, the two anterior of which are merely 
rounded crests; in each depression between the 
teeth, a small fissure is visible, dividing their bases 
from one another ; postero-lateral margin somewhat 
depressed; front four-lobed, the two middle lobes 
approximate, rounded at tip, and considerably pro- 
duced, the outer ones small, but very distinct ; an- 
terior feet stout, with a few punctures scattered 
over the surface ; hands with a great crest above, 
vol. vxxi. — 1839. 15 
