The Nautilus. 



Vol. XXX. NOVEMBER, 1916. Xo. 7 



EULIMASTOMA. A NEW SUBGENUS OF PYRAMIDELLIDS AND REMAEKS 

 ON THE GENUS SCALENOSTOMA. 



BY PAUL BARTSCH. 



Additional material received by the United States National 

 Museum makes it necessar\' to create a new subgenus for the 

 Pyramidellids typified by Odo.stomin (^Scalenosto)na) dotella Dall 

 and Bartsch (Bull. 68, U. S. N. M., p. 230, 1909). Scnlenostovia 

 must be referred to the familj' Melanellidae {= Exdimidae) . 



There is a wonderful resemblance between Eulimnsioma and 

 Scalenostoma as far as texture of shell and sculpture are con- 

 cerned, and it was this resemblance and the absence of repre- 

 sentatives of the genus Scnlenostovia that caused me to consider 

 this a Pyramidellid in the past. Material now at hand shows 

 that Odostomia (Eidimastoma) dotella Dall and Bartsch has an 

 obliquely tilted, deeply immersed nucleus, a Pyramidellid 

 character, while Scalenostoma has the usual attenuated, acute, 

 non-sinistral tip. 



The following synonymy shotdd be noted : 



Scalenostoma Deshayes, Cat. Moll. He de la Reunion, pp. 58- 

 60, PI. vii, figs. 26-8, 1863. Type Scalenostoma carinatum Des- 

 h&jea=Subeulima Souverbie, Joum. de Conch, xxiii, p. 296, 

 1875. Type Subeulima lamberti Souverbie. 



The west American members of the genus Scalenostoma are: 



Scalenostoma rangii (de Folin). 



Chemnitzia rangii de Folin. Les Meleagrinicoles p. 61, PI. 6, 

 fig. 1, 1867. Odostomia (Scalenostoma) rangii, Dall and Bartsch 

 Bull. 68, U. S. N. M., p. 230, PI. 30. fig. 2, 1909. Odostomia 



