CLASS GASTROPODA 
135 
twenty-eight upon the penultimate post-nuclear turns. Intercostal spaces 
about double the width of the ribs, shallow, rounded, crossed by six, 
equal and equally spaced, strongly incised, spiral lines which extend 
stronger upon the sides of the ribs and feebly over their summits. In 
addition to this sculpture, the spire is marked by many fine lines of growth 
and many fine spiral striations between the incised lines. Sutures well- 
marked, simple. Periphery of the last whorl subangulated, marked by 
the feeble continuations of the axial ribs, which disappear at the periphery. 
Base short, marked by eleven continuous, equal, strong, incised, spiral 
lines, which are more closely spaced above the umbilical area than at the 
periphery; the space between the first basal incised line and the first supra- 
peripheral one being a little wider than the space inclosed between the 
spiral lines on the spire. Aperture subquadrate, outer lip thin, showing 
the external sculpture within; columella almost straight and vertical, 
slightly revolute. (Dali and Bartsch.) 
Type in United States National Museum, No. 168867. Type locality, 
U.S. Bureau of Fisheries Steamer “Albatross” Station 3192, Esteros 
Bay, California. 
Range. Esteros Bay to San Diego, California. 
Turbonilla antemunda Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 88; PI. 8, figs. 15, 15a. 
Shell broadly conic, milk-white, with a moderately broad pale-yellow 
band at the periphery and another at the middle of the whorls between the 
sutures of the same width. Nuclear whorls two and three-fourths, heli¬ 
coid, having its axis at right angles to that of the succeeding turn, in the 
first of which it is about one-third immersed. Post-nuclear whorls mod¬ 
erately rounded, appressed at the summit, strongly contracted at the 
periphery, somewhat overhanging, ornamented by well-developed, narrow 
axial ribs, which become decidedly enfeebled toward the summit. Of 
these there are sixteen upon the first to fourth, eighteen upon the fifth 
to seventh, twenty upon the eighth, twenty-two upon the ninth and penul¬ 
timate whorl. Intercostal spaces about two and one-half times as wide as 
the ribs, ornamented with a double series of spiral markings, the first of 
which consists of seven strongly incised and subequally spaced pits be¬ 
tween the sutures, the third and fourth of which above the periphery 
bound the color band and are a little closer spaced than the rest. The 
first one below the summit passes over the axial ribs and gives them a 
truncated appearance; the others pass up the sides of the ribs but do not 
cross them. The second series of spiral markings consist of very fine 
lines, of which three occur between the peripheral series of pits and the 
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