CLASS GASTROPODA 
131 
those remaining, the same number upon the penultimate turn. Intercostal 
spaces about half as wide as the ribs, marked by six, equal and equally 
spaced, spiral rows of pits, the last of which is at a little greater distance 
from the summit than its fellow. Sutures very faintly indicated. Periph¬ 
ery of the last whorl somewhat angulated. Base short, well-rounded, 
marked by about a dozen fine, wavy, equal and equally spaced, spiral 
lines. Aperture rhomboidal; outer lip thick; columella moderately strong, 
slightly sinuous and somewhat reflected. Length, 10.2; diameter, 2.7 mm. 
(Dali and Bartsch.) 
Type in United States National Museum, No. 160210. Type locality, 
San Pedro, California. 
Range. Known only from type locality. 
Turbonilla morchi Dali and Bartsch, 1907 
Plate 54, figs. 1, la; Plate 55, figs. 6, 6 a 
Proceedings of the United States National Museum, 33:505; PI. 45, figs. 1, la. 
Shell broadly elongate-conic, the posterior third of the exposed portion 
of the whorls on the spire and a narrow area about the umbilical region 
flesh-colored, the rest of the shell light chestnut-brown. Nuclear whorls 
two and one-half, small, smooth, forming a depressed helicoid spire which 
has its axis at right angles to the axis of the succeeding turns and is about 
one-fifth immersed in the first of them. Exposed portion of the post- 
nuclear whorls flattened in the middle, posterior fourth sloping gently 
toward the summit, which is closely appressed to the preceding turn; 
the anterior portion slopes more abruptly, roundly toward the periphery. 
The whorls are ornamented by strong rather distantly spaced, moderately 
acute, slightly protractive axial ribs, of which eighteen occur upon the 
first three, sixteen on the next three, eighteen on the seventh, and twenty 
upon the penultimate turn. The ribs weaken slightly and become some¬ 
what flattened as they approach the constricted sutures. Intercostal 
spaces broad, almost double the width of the ribs, crossed by seven, 
equal and equally spaced, deeply incised spiral lines, which extend up on 
the sides of the ribs and feebly across them. The space between the 
second and third lines appears slightly nodulose on the ribs. Periphery 
of the last turn angulated, crossed by the continuations of the ribs, which 
disappear as they pass on to the short and well-rounded base. Base 
marked by thirteen continuous incised spiral lines of about equal strength 
which are much more closely spaced near the umbilicus than the periphery, 
the distance between the succeeding striations diminishing in regular ratio 
from the periphery to the umbilical area, the first two below the periphery 
being considerably more distantly spaced than the rest, the spaces in- 
1429 ] 
