192 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



ing and measures: Length, 10.3 mm,; greater diameter, 6.0 mm.; 

 lesser diameter, 5.0 mm. 



OPISTHOSIPHON (BERMUDEZSIPHONA) BERMUDEZI, new species 



Plate 14, Figure 6 



Shell smaU, ovate, thin, pale brown, with yellowish peristome. 

 Nuclear whorls 2, strongly rounded, microscopically granulose. Post- 

 nuclear whorls inflated, strongly rounded, and marked by almost 

 vertical sublamellose axial ribs, which are rather distantly spaced, of 

 wliich 22 occur on the first and 47 on the last of the remaining turns in 

 the type. These ribs form slender denticles at the summit. Inter- 

 costal spaces broad, marked by microscopic axial threads. Suture 

 very strongly constricted. Periphery inflated, strongly rounded. 

 Base short, inflated, strongly rounded, and marked by the continua- 

 tion of the axial ribs and by several strong spiral cords at the outer 

 edge of the mnbilicus and feebler ones within. These cords render 

 the axial ribs scalloped. Umbilicus rather large. Aperture broadly 

 oval; peristome double, the inner exserted and slightly reflected; the 

 outer rather broadly expanded, forming a slight auricle at the posterior 

 angle of the aperture, marked by concentric lameUae. Operculum 

 typically opisthosiphonid. Siphon at the posterior angle of the 

 aperture behmd the peristome directed into the suture. 



This species appears rather widely distributed among the hills about 

 Vega Alta, Santa Clara Province. We have seen it from Vereda del 

 Abra, Lomas Murcielagos, Sinaloa, and Sola. 



The type, U.S.N.M. No. 535466, comes from Loma Murcielagos; it 

 has 3.5 whorls remaining and measures: Length, 8.6 mm.; greater 

 diameter, 5.6 mm.; lesser diameter, 4.7 mm. 



Animals of this species, collected by Bartsch at Loma Murcielagos, 

 near Vega Alta, on August 16, 1928, were described by him as being 

 buff above with a decidedly rosy tinge behind the tentacles. Snout a 

 little paler at the tip. Tentacles bright buff, tipped with bluish 

 black. Sides of the body and the deeply cleft sole of the foot pale 

 olivaceous. The motion is steady. 



OPISTHOSIPHON (BERMUDEZSIPHONA) ANDREWSI Welch 



Plate 14, Figure 1 



1929. Opisthosiphon andrev)si Welch, Nautilus, vol. 42, p. 98, pi. 5, fig. 6. 

 1934. Opisthosiphon andrewsi Welch, Nautilus, vol. 47, p. 130, pi. 11, fig. 5. 



Shell small, ovate, thin, pale brown with pale yellow peristome. 

 Nuclear whorls decollated in our specimens. Postnuclear whorls 

 strongly rounded, marked by very distantly spaced lamellose axial 

 ribs, which bear feeble indications of scallops, 17 of which occur on the 

 first and 23 on the last of the remaining turns. These ribs are ex- 

 panded at the summit into narrow, low cusps. The intercostal spaces 



