1918 | Packard: Molluscan Fauna from San Francisco Bay 315 
PYRAMIDELLIDAE 
Turbonilla Risso 
Turbonilla (Pyrgolampros) franciscana Bartsch 
Plate 36, figures 8 and 9 
Turbonilla (Pyrgolampros) franciscana, Bartsch (1917), p. 645, pl. 42, fig. 2. 
Description.—This species was originally described by Bartsch, as follows: 
“*Shell elongate conic, flesh colored excepting a broad chestnut band, which 
covers the median third of the last whorl. This dark band really consists of 
two chestnut colored zones, the anterior of which embraces half the band, 
while the posterior is equal to one-fourth of the dark area; the two being 
separated by a zone of a little lighter shade, which is as wide as the posterior 
zone. Nuclear whorls decollated in all the specimens seen. Postnuclear whorl 
rather high between the sutures, feebly shouldered at the summit, and slightly 
constricted at the periphery. Early postnuclear whorls marked by low, rounded, 
broad, almost vertical axial ribs, which are wider than the shallow impressed 
spaces that separate them. On the later whorls the axial ribs become quite 
obsolete. On the first of the postnuclear whorls, there are eighteen of these ribs; 
on the second to fourth, twenty; on the fifth they become decidedly feeble and 
on the remainder they are not at all differentiated. In addition to the axial 
sculpture, the surface of the shell is marked by very fine, wavy, closely spaced 
spiral striations. Periphery of the last whorl well rounded. Base moderately 
long, well rounded, marked by lines of growth and spiral striations comparable 
to those on the spire. Aperture broadly oval; outer lip thin, showing the color 
markings within. Columella curved, somewhat twisted and slightly revolute; 
parietal wall glazed with a thin callus.’’ 
The type, and seventeen specimens, Cat. No. 214435, U.S. N. M., was dredged 
by the U.S. 8. ‘‘Albatross’’ at station D 5743, in 10-15% fathoms, on very fine 
sand and mud bottom, San Francisco Bay, California. The type has lost the 
nucleus and probably the first of the postnuclear turns. The eight remaining 
measure: length 6.8 mm., diameter 2 mm. 
There are three additional lots of specimens in the collection of the U. 8. 
National Museum, likewise dredged by the U. 8. Bureau of Fisheries Steamer 
“* Albatross’’ in San Francisco Bay. These are Cat. No. 214433, 3 specimens, 
from station D 5729 in 4%, fathoms on sandy mud bottom. Cat. No. 214436, 
4 specimens from station D 5703 in 81% fathoms on mud bottom. 
This species belong to the obsoletely sculptured group of Pyrgolampros, 
embracing halistrapta, pesa, rinella, lituyana, oregonensis.’” 
Height, 3 to 6.8 mm. 
Occurrence.—At stations D 5703 (5, 1), D 5704 (1), D 5705 ( 
D 5723 (6), 5729+ (2), D 5740 (7, 1), D5743t (34), D5744 (2 
Dsat (hp Di ol63.(4). DSaT64 (sy 1); DibT8l i@), Disrsd: (a), 
D 5786 (1), D 5799 (4), D 5822 B (40), D 5825 A (66), D 5826 A (1), 
D 5828 B (64), D 5830 A (12), D 5831 (2), D 5836 (24), D 5839 (48), 
D 5840 (8), Sausalito (1). 
This new species was dredged at two of the outside stations and 
at 23 stations within the middle and lower divisions of the bay. Living 
3), 
Os 
