1918] = Packard: Molluscan Fauna from San Francisco Bay 333 
Both Carpenter and Wood and Raymond recognized this species 
from the vicinity of San Francisco. It is recorded at twenty-one of 
the ‘‘ Albatross’’ stations, having a distribution pattern similar to that 
of Nassa fossata. Living specimens were obtained only within the 
middle division of the bay at depths ranging from 114 to 29 fathoms. 
A variety of bottom types are represented at these stations. The 
species appears to prefer the muddy localities in preference to the 
sandy ones. 
Range—Sitka, Alaska, to San Diego, California (Cooper). 
Nassa perpinguis Hinds 
Plate 35, figure 13 
Nassa perpinguis Hinds (1844a), p. 36, pl. 9, figs. 12, 13; Tryon (1882a), 
p- 56, pl. 17, fig. 319; Arnold, R. (1903) p. 234. 
Description.—This species is described by Arnold (1903) as follows: 
‘Shell small, conical; spire elevated; apex subacute; whorls seven, convex, 
abruptly truncated at posterior margin, forming a spiral table; ornamentation 
consists of sharp, spiral ridges with slightly wider interspaces, and posteriorly 
sloping transverse ridges, the whole giving a decidedly cancellate appearance 
to the surface; suture deeply impressed, distinct; aperture subovate; inner 
portion of aperture ridged by spiral sculpture; outer lip thin; inner lip thinly 
inerusted; columella twisted and spirally ornamented; groove on upper part of 
columella prominent; canal short, curved.’’ 
Height, 3 to 33 mm. 
Occurrence —At stations D 5754 (4), D5755 (1), D5785 (24, 
2) DiorSG) (OS) s Dioist™ (22,9), Di5189) (72: 48), 5790) (2); 
D 5791 (5, 9), D 5792 (8, 3), D 5826 B (1), D5841 (1), and west of 
the Farallon Islands (3). 
According to Cooper, San Francisco is the northern limit of the 
range of this species. Restricted to stations from the open ocean and 
the middle division of the bay, except for a single specimen near the 
Ferry Building at San Francisco. Living specimens were dredged 
at depths ranging from 414 to 815 fathoms on bottoms that are pre- 
dominantly sandy. 
Range.—San Francisco, California, to Lower California (Cooper). 
Ilyanassa Stimpson 
Ilyanassa obsoleta (Say) 
Plate 35, figures 1la and 11b 
Nassa obsoleta Say (1822), p. 232. 
Tlyanassa obsoleta Tryon (1882a), p. 60, pl. 18, figs. 347-349; Sumner, 
Osburn, Cole, and Davis (1913), p. 710, chart 168. 
