NEW MOLLUSKS FROM SANTA ELENA BAY, ECUADOE. 



By Paul Bartsch. 



Curator of iloUusks, United States National Museum. 



Dr. R. A. Olsson has recently submitted to the United States Na- 

 tional Museum a small lot of Pyramidellidae and Melanellidae col- 

 lected by him in Santa Elena Bay, Ecuador. This is the first ma- 

 terial that we have had from this locality. In fact, very little has 

 been collected excepting the gathering made during the forties of the 

 last century at this place by Hugh Cuming, which did not stress 

 the minute species. 



A very careful comparison of these specimens with the magnifi- 

 cent Panama series in the United States National Museum reveals 

 the fact that every species represented in this gathering proves to be 

 undescribed. This should certainly stimulate future efforts in this 

 region, as well as in the territory to the south of it, from which very 

 little minute material has come to hand. 



All the species described in this paper are based upon Doctor 01s- 

 son's collecting at Santa Elena Bay. The specimens have been do- 

 nated to the United States National Museum. 



PYRAMIDELLA (LONGCHAEUS) ELENENSIS, new species. 



Plate 1, fig. 5. 



Shell elongate-conic, pinkish white, with a lighter median zone on 

 each whorl. Nuclear whorls decollated. Postnuclear whorls flat- 

 tened, narrowly tabulatedly shouldered at the summit, which is also 

 minutely crenulated. Periphery of the whorls marked by a slender 

 incised groove, crossed by numerous minute riblets and bounded 

 posteriorly by a rather strong keel. The summit of the succeeding 

 whorls falls below the groove and causes the suture to appear deeply 

 channeled and finely denticulated. Base short, well rounded, smooth. 

 Aperture fractured in both of our specimens; outer lip provided with 

 four conspicuous spinal lamina? within, of which two are posterior 

 and two anterior to the peripheral sulcus. Columella short, very 

 stout, provided w^ith a very broad lamellar fold about one-third of 

 the distance from its insertion to the tip anterior to the insertion. 



No. 2551. — Proceedings U. S. National Museum, Vol. 66, Art. 14. 



100827 — 24 1 



