of the Pacific Shores of North America. 471 
LEUCOSILIA JURINII. Bell. 
Guaia Jurinii, Dx Saussure; Rev. et Mag. de Zoül. 1853, v. 365, Pl. XIII. f. 4. 
Leucosilia Jurinii, BELL; Trans. Linn. Soc. xxi. 295, Pl. XXXII. f. 1. 
Mazatlan, ( Verreaux.) 
us. Brit. 
RANDALLIA. nov. gen. 
Carapax ovalis, subglobosus, fer? levis, politus, dentibus duobus posticé arma- 
tus. Regiones pterygostomiani angulati. Frons angustata sed crassa, in 
dens et partem super-mobilem retractam antenne celans. Epistoma ex com- 
paratione ampla. Maxillipedes et pedes ut in Persephond. 
The species upon which this genus is founded was placed 
in Ilia by RaxpaLL, and in Guaia (Persephona) by Giszes. 
Its characters will, however, exclude it from both of these 
genera, although it approaches closely to the latter in its 
general appearance. The following are its distinctive fea- 
es. The carapax is not depressed, and is armed with 
but two teeth posteriorly ; the surface is mostly smooth and 
ungranulated. Anterior extremity thick. Antennary fosse 
small, oblique, and very deep. Basal article of internal 
antenne somewhat expanded, operculiform, almost com- 
pletely closing the aperture of the fossa when the antenna 
‘Stetracted within it. The fossæ do not immediately border 
9n the buccal margin as in Persephona, but are separated 
from it by a considerable space, so that the epistoma pre- 
sents a greater surface than is usual in the family. 
RANDALLIA ORNATA. Stimpson. 
Plate XIX. f. 3. 
2 Penata, RANDALL; Jour. Acad. Nat. Sci. Philad. viii. 129. 
nala ornata, GIRBES ; Proc. Am. Assoc. 1850, p. 186. as 
ndallia ornata, Stimpson ; Proc. Bost. Soc. Nat. Hist. vi. 85. 
In this species there are generally a few granules on the 
Stomachal region anteriorly, and on the intestinal poste- 
