272 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 42. 



the remainder are not so wide and are less regular. Aperture mod- 

 erately large, ovate; posterior angle acute; outer lip thin; inner lip 

 obhque, somewhat curved, and sHghtly revolute; parietal wall glazed 

 with a thin callus. 



The type (Cat. No. 211554, U.S.N.M.) comes from San Diego Bay, 

 Cahfornia. It has lost the nucleus and probably a portion of the 

 first post-nuclear turn; the nine remaining measure: Length, 7.2 

 mm.; diameter, 2.2 mm. 



This species follows Turhonilla (Pyrgiscus) tenuicula in the key. 



TURBONILLA (MORMULA) SCAMMONENSIS, new species. 

 Plate 36, fig. 5. 



Shell elongate-conic, rather stout, pinkish. Nuclear whorls decol- 

 lated. Post-nuclear whorls increasing rapidly in size at first, then 

 subcylindric ; moderately rounded on the early whorls, flattened on 

 the later; narrowly, tabulatedly shouldered; marked with strong, 

 regular, almost vertical, axial ribs, which extend strongly from the 

 summit to the periphery; of these ribs, 18 occur upon the third and 

 fourth, 20 upon the fifth, 22 upon the sixth and seventh, 24 upon 

 the eighth, and 26 upon the penultimate whorl. On some of the 

 whorls there is a tendency toward the formation of a low varix, 

 due to the fusion of two ribs. Intercostal spaces a little narrower 

 than the ribs, strongly impressed. In addition to the axial ribs, the 

 whorls are marked with incised spiral lines; of these, five occur 

 between the sutures upon the first six whorls, one being at the peri- 

 phery, another at the middle between the sutures, and two between 

 these; these four divide the space between them into three equal 

 parts; the fifth spiral line is a little nearer the median spiral line 

 than the summit, leaving a broad, plain band at the summit. On 

 the seventh whorl there is an intercollated, fine, spiral line on the 

 middle of the space between the median and the one anterior to it, 

 while on the next whorl an additional spiral line makes its appear- 

 ance in the same raised band and continues over the rest of the 

 whorls. Summits of the whorls slightly cuspidate and somewhat 

 exserted. Sutures strongly marked. Periphery of the last whorl 

 weU rounded. Base moderately long, weU rounded, marked by seven 

 equal, incised, spiral lines, which are almost equally spaced, and very 

 feeble continuations of the axial ribs. Aperture moderately large; 

 posterior angle acute; outer lip thickened with an internal caUus, 

 and reenforced by four strong, spiral lirations; inner lip stout, 

 slightly curved and somewhat revolute, provided with a strong fold 

 at its insertion; parietal wall glazed with a thin caUus. 



The above description is based upon two specimens collected by 

 Mr. Henry Hemphill, in Scammon's lagoon, Lower California. One 



