CRUSTACEA. 
117 
from the middle, but here there are frequently only 
four equidistant frontal teeth. 
Genus Trapezium, (Latr.) 
T. cymodoce, (Cancer cymodoce , Herbst.) (Tra- 
pezium dentifrons, Latr.) Mus. Acad. 
Several specimens, well agreeing with the figure 
of T. cymodoce , have been brought from the Sand- 
wich Islands by Mr. Nuttall and J. K. Townsend. 
Fam. Portunidce. 
Genus Lupa, (Leach.) 
L. sanguinolenta, (Herbst.) 
Many specimens, brought by Mr. Nuttall and 
J. K. Townsend from the Sandwich Islands. 
Genus Thalamita, (Latr.) 
T. pulchra. 
Testa subhexagona, coeruleo-maculata, margine utrinquk 
7-dentata, dentibus secundo et quarto minimis; fronte 
S-dentata. 
Carapax somewhat hexagonal, disk with several 
transverse, distinctly elevated lines, formed of very 
minute granules; post frontal, and antero-lateral 
portion granulated, some rugosities on each side 
behind the middle, remainder of the surface nearly 
smooth ; front with eight large, elongated, nearly 
equal, obtusely rounded teeth, those on one side a 
little diverging from the corresponding ones on the 
other, and all of them somewhat flattened above ; 
