508 Stimpson on the Crustacea and Echinodermata 
most interesting additions to the fauna of Washington 
Territory. 
Mus. Smithsonian. 
LIVONECA VULGARIS. Stimpson. 
PL RAIL. £9. 
Livoneca vulgaris, Stimpson; Proc. Bost. Soc. Nat. Hist. vi. 88. 
This is the common fish-louse of the San Francisco mar- 
ket. It is variable in shape, often distorted, and frequently 
abruptly widened at the fifth thoracic segment. Head 
small, wider than long; inner antennæ somewhat shorter 
and stouter than the outer or posterior ones. Epimeral 
pieces narrow, separated from the tergal piece in the ante- 
rior segments by a distinct suture, in the posterior segments 
by a deep incision; the point reaching the margin of the 
tergum in the anterior four segments, and not extending 
much beyond it in the posterior three. Posterior thoracic 
segment deeply sinuated for the reception of the middle 
portion of the anterior abdominal segments. Lamelliform 
caudal segment always transverse in the adult. Color yel- 
lowish gray; posterior pair of false feet always black. 
Length, 1.5; breadth, 0.9 inch. It resembles L. Desmarestit 
in general appearance. 
Parasitic on fish of several kinds. ‘Tomales Bay, (Sam- 
uels;) San Francisco Bay, (Stimpson ;) Monterey, (Trow- 
' bridge.) 
Mus. Smithsonian; Bost. Soc. 
EGA MICROPHTHALMA. Dana. 
JEga microphthalma, Dana; Proc. Acad. Nat. Sci. Philad. 1854. vii. 176. 
Hab. * California,” (Le Conte ;) Monterey, ( Taylor.) 
Mus. Smithsonian. 
The body in this species is generally considerably penc 
in the young than in the adult. Upper surface covered wit 
