656 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



TURBONILLA (PYRGISCUS) CORTEZI, new species. 



Plate 45, fig. 12 ; plate 42, fig. 7. 



Shell rather large, elongate conic, pale yellowish brown. Xiiclear 

 whorls 2^, well rounded, formi ng a decidedly depressed helicoid spire, 

 the axis of which is at right angles to that of the succeeding turns 

 in the first of which the tilted edge is about one-fifth immersed. 

 Early postnuclear whorls well rounded, the later ones almost flat- 

 tened, all appressed at the summit and marked by slender, well- 

 roimded, low, decidedly retractive axial ribs, of which 24 occur upon 

 the first four turns, 22 upon the fifth and sixth, 26 upon the penulti- 

 mate, and 30 upon the last turn. These ribs become somewhat en- 

 feebled and expanded toward the summit. Intercostal spaces about 

 two times as wide as the ribs, crossed by seven spiral series of pits, 

 of which the second, third, sixth, and seventh are equal and stronger 

 than the rest; the other three being about half as wide and equal. 

 In addition to the above sculpture the entire spire is marked by fine 

 incremental lines and equally fine spiral striations, the com- 

 binations of which give to the surface a clothlike texture. 

 Suture feebly impressed. Periphery of the last whorl well rounded. 

 Base moderately long, strongly rounded, marked by incremen- 

 tal lines and 8 rather broad, somewhat wavy, subequal, and 

 subequally spaced spiral lines. The white color of these and the 

 incised stronger lines on the spire stand out in marked contrast to 

 the ground color. Aperture elongate oval ; slightly effuse anteriorly ; 

 posterior angle acute ; outer lip thin, showing the external sculpture 

 within; inner lip almost straight, slightly revolute; parietal wall 

 glazed with a thin callus. 



The type and two additional specimens. Cat. No. 267722, 

 U.S.N.M., were dredged in shallow water in Santa Maria Bay, Lower 

 California. The type is an adolescent specimen and has 8f post- 

 nuclear turns, and measures — length, 6.5 mm. ; diameter, 1.9 mm. 



One of the other specimens is adult, but has lost the nucleus and 

 probably the first three postnuclear turns. The eight remaining 

 measure— length, 8.3 mm.; diameter, 2.5 mm. This specimen also 

 enables us to say that the last whorl is inflated and that the axial 

 ribs become obsolete on this turn. 



TURBONILLA (PYRGISCUS) TECALCO, new species. 

 Plate 45, fig. 4. 



Shell broadly elongate conic, milk white. Nuclear whorls 2^, well 

 rounded, forming a decidedly depressed helicoid spire, having its 

 axis at right angles to that of the succeeding turns, in the first of which 

 it is about one-fourth immersed. Postnuclear whorls flattened in the 

 middle, weakly rounded at the summit, marked by very regular, 



