WEST AMERICAN PYRAMIDELLID MOLLUSKS. Ill 



TURBONILLA (MORMULA) LORDI E. A. Smith. 



Plate 11 , figs. 4, 4a. 



Chemnitzia lordi E. A. Smith, Ann. Mag. Nat. Hist., vol. 6, 1880, p. 288. Tur- 

 bonilla (Mormula) lordi Dall and Bartsch, Proc. U. S. Nat. Mus., vol. 33, 

 1907, pp. 510, 511, pi. 45, figs. 7, 7a. 



Shell very largo, light brown to pale yellowish-white, variously 

 banded. Nuclear whorls two, smooth, helicoid, moderately elevated, 

 having their axis at right angles to the axis of the succeeding turns 

 and about one-fourth immersed in the first of them. Post-nuclear 

 whorls well rounded, ornamented by heavy, broad, low axial ribs, of 

 which about 14 occur upon the second, 16 upon the eighth, 22 upon 

 the eleventh, and 30 upon the penultimate whorl. Intercostal spaces 

 not deeply depressed, about as wide as the ribs, ornamented by about 

 12 to 15 irregularly spaced spiral striations between the sutures; those 

 near the summit of the whorls are closer and more feeble than those 

 near the periphery of the whorls. Sutiu-es strongly impressed, some- 

 what wavy. Periphery of the last whorl somewhat angulated in 

 young specimens, moderately well rounded in adults. Base rather 

 short, marked by faint continuations of the axial ribs and faint wavy 

 spiral striation. Aperture subrhom.bic, posterior angle obtuse, outer 

 lip thin, showing the external sculpture and banding within; columella 

 stout, slightly twisted and revolute, provided with an oblique internal 

 fold. The color markings in the specimen here described and figured 

 (fonsist of a pale yellowish-brown band, about a quarter of the width 

 of the whorl between the sutures, covering the posterior part, fol- 

 lowed by a narrow band of the yellowish-white ground color, which is 

 followed by a band of brown a little darker than the first and about as 

 wide as the last-named white band; then a broad pale white band, 

 lastly a narrow pale yellow one above the periphery finishes the mark- 

 ing between the sutures. The periphery is marked by a narrow band 

 of white followed by a deep brown one which shades gradually to the 

 white about the umbilical region. 



The characters which ally this species to Mormula are only feebly 

 developed, now and then two ribs become fused and suggest a varix; 

 the internal lirations, too, are only very feebly expressed and appear in 

 the aperture of only one specimen. The specimen figured has 14 post- 

 nuclear whorls and measures: Length 20.8 mm., diameter 5.1 mm. It 

 was collected in 12 fathoms at Sitka Harbor, Alaska, and is Cat. no. 

 160492, U.S.N. M. No. 160069, U.S.N. M., contains 7 individuals 

 from the same locality; no. 133234, U.S.N.M., has 2 from Port 

 Orchard, Washington, and no. 4480, U.S.N.M., 1 from Puget Sound, 

 Washington. Seven specimens were collected by Rev. G. W. Taylor 

 at Banks Island, British Columbia. One of these, a young individual 



