APPENDIX 
281 
rounded. Base short, strongly rounded, narrowly umbilicated, marked like 
the spire. Aperture subquadrate; posterior angle decidedly obtuse; outer 
lip thin; columella almost straight, reflected over and appressed to the 
base for its posterior fifth; parietal wall covered with a thin callus. 
Type in United States National Museum, No. 362455. Type locality, 
San Clemente Island. Length, 5 mm.; diameter, 2.1 mm. 
Subgenus Pyrgolampros (see pp. 87 and 107) 
Turbonilla stelleri Bartsch, 1927 
Proceedings of the United States National Museum, 70:6; PI. 2, fig. 4. 
Shell very regularly elongate-conic, flesh-colored, with a broad zone of 
pale brown which extends from a little anterior to the periphery on the 
base posteriorly over half of the whorl. Nuclear whorls decollated. Post- 
nuclear whorls appressed at the summit, which is very narrowly shoul¬ 
dered, decidedly flattened in the middle, and moderately constricted at the 
suture, marked by very regular, vertical axial ribs, of which 16 occur upon 
all but the last two turns, on which 18 are present. These ribs are about 
as wide as the spaces that separate them, on the first three turns; on the 
middle turns they are only half as wide, while on the last turn the inter¬ 
costal spaces are about one and one-half times as wide as the ribs. In 
addition to the axial ribs the whorls are marked by fine lines of growth 
and numerous, very closely spaced spiral striations, which extend over 
both ribs and intercostal spaces. Periphery of the last whorl well-rounded. 
Base short, well-rounded, marked by the feeble continuations of the axial 
ribs, which evanesce shortly after passing the periphery, and numerous, 
closely spaced spiral striations. Aperture large, subquadrate, posterior angle 
obtuse; outer lip thin showing the external sculpture and color markings 
within; columella somewhat twisted, almost vertical, slightly reflected and 
appressed to the base for the posterior third of its length; parietal wall 
covered with a thin callus. 
Type in United States National Museum, No. 362146. Type locality, 
Shuyak Strait, Afognak Island, Alaska. Length, 8.3 mm.; diameter, 
2.2 mm. This, species is a member of the Turbonilla (Pyrgolampros) halia 
Dali and Bartsch group. It differs from the other known members by its 
coloration and flattened whorls, as well as by its size. 
Turbonilla ilfa Bartsch, 1927 
Proceedings of the United States Natioml Museum, 70: 7; PI. 1, fig. 1. 
Shell very large. Nuclear whorls decollated. The eight and a quarter 
turns remaining narrowly shouldered at the summit, slightly rounded in 
the middle, somewhat contracted toward the base, marked by strong, well- 
[ 579 1 
