380 Gould's Descriptions of Shells 
Long diameter seven eighths of an inch ; short diameter not quite 
half an inch; height one fifth of an inch. 
Inhabits La Paz, Gulf of California. Lieut. Green. 
It has the form of S. haliotoideus, and is nearly as smooth as S. 
levigatus. It is about the size of S. planus, and has the compressed 
form of S. depressus. Its honey-yellow color is peculiar. 
NARICA OVOIDEA (Pl XIV. Fig.10.) 
T.ovoidea, solida, albida, costis planulatis politis ad 11 cincta, interspatiis 
duplo angustioribus concinne? clathratis ; spira acuta, anfr. 4, superne tabulatis, 
imo magno, ovato: apertura ovata; labro crenulato; columella tenui, an- 
trorsum concava, plicá medianá instructá; umbilico conspicuo, profundo. 
Shell ovoid, solid, dingy white, surrounded with well marked 
grooves and square shining ribs, about eleven on the large whorl 
and five on the others, the grooves about half the width of the ribs, 
and delicately clathrate with longitudinal bars; spire acute, whorls 
four, shouldered above, the last whorl composing the greater part of 
the shell.. Aperture half the length of the shell, ovate, ribs render- 
ing the outer lip crenate; inner lip rather sharp, concave in front, 
slightly attached to the whorl above and having a delicate fold at . 
the middle. . Umbilicus well marked and deep. 
Length seven twentieths of an inch; breadth three twentieths of 
an inch. 
Purchased at Mazatlan. Col. Jewett. 
This curious shell it is difficult to classify; perhaps there is no 
genus now defined which can properly receive it. Littorina (?) 
angistoma and excavata C. B. Adams, seem to belong to the same 
group. 
TEREBRA ARGUTA (Pl XIV. Fig. 19-) 
T. parva, acicularis, nitida, plicis longitudinalibus rectis acutis ad 10 ornats, 
interspatiis concavis; albida propè suturam fusco zonata, et interdum ines 
flexuosis picta; apertura angusta, lunaris; anfr. 8 planulatis, ultimo ad basim 
ETEA 
Shell small, acicular, very acute and slender, glistening, ome 
posed of about eight flattened whorls, having on each about "^ 
acute longitudinal folds, the spaces between fluted; a gad y rm 
lines around the base of the last whorl; aperture narrow — 
