480 K. J. Bush — Notes on the family PyramidellidcB. 



as the exceedingly fine microscopic striae, always discernible 

 under high power objectives, are not taken into consideration. 

 Therefore its relation to the subgenus Strioturbonilla (p. 79) 

 seems imaginary. This subgenus is described by Sacco, " Testa 

 sicut in Turbonilla (stricta sensu) sed transversin striolge par- 

 villimas (sub lente vix visibiles)," etc., etc., and his tigure of 

 S. apicina shows many very tine, distinct, incised spirals 

 between the ribs and on the base, similar to the sculpturing 

 found in the true T. interrupta (p. 481). 



The Turbonilla polita Verrill, 1882 (p. 75) does not con- 

 flict with Odostomia polita Bivona, 1832 ; nor Pease, 1867. 



For discussion of the genus Turbonilla (p. 76) and type 

 see p. 483. The name nivea is extensively used in this group, 

 but Turbonilla nivea (Stimpson, 1851 and 1853) from 40 fms. 

 off Grand Menan, N. B., has priority. The shallow water 

 species described and figured as nivea by Bartsch (p. 77) is not 

 like the typical specimen from U. S. F. C. Station 871, off New- 

 port, K. I. in 115 fins., 1880, described by Verrill* in 1881, (the 

 specimen cited from Station 949 is the true nivea). The axial 

 ribs end just above the deep suture; the intercostal spaces 

 showing a basal curve, thus leaving a very narrow, smooth, 

 sutural area. The whorls are less rounded than indicated in 

 the figure, p. 484, f. 1. The nivea Bartsch is a typical 

 T. stricta Verrill. In a lot of over 20 specimens, from Vine- 

 yard Sound, there is great variation in the number and width 

 of the axial ribs. The largest specimen, having 10 post- 

 nuclear whorls, is like Bartsch's figure 9, Plate II, but is not 

 the T. stricta Bartsch, figure 6, which is a typical T. mqualis 

 Say (p. 78). [See p. 484, f. 5, from Woods Holl, Mass., 1882.] f 



The Trip?tychus niveus Morch, 1875 (type and only species 

 of the genus) is described as having a few spiral lirge ; the 

 Urge extending into the aperture forming three plications on 

 the columella. Aperture subemarginate anteriorly, somewhat 

 excavated below the lirse. Nucleus reversed. 



The nucleus is the only character showing any relation to 

 the Pyramidellidge. The aperture would exclude it, as it 

 shows nearer affinity to the genus Cerithiopsis. Dr. Dall, 1889 

 (also Dall and Guppy, 1896), suggested its being synonymous 

 with Oscilla, which seems hardly possible ; indiscreta Guppy, 

 1896, is described and figured as Triptychus (Oscilla). The 

 Pyramidellida vincta Dall is placed as a synonym of T. 

 niveus Morch by Tryon, 1 886. Although stating that " The 

 shell is scarcely a Pyramidella— the sculpture and plications 

 are different," Tryon uses Triptychus as a section of the Pyra- 

 midellidge, and Dall and Bartsch, 1904, p. 5. as a subgenus. 

 The Dunheria falcifera Watson, 1885, from Bermuda may 

 prove to have affinity to this group. 



* Proceedings U. S. National Museum, vol. iii, 1881, p. 379. 



