a 4 transverse to the anterior border); posterior scar subcircular, 
superficial; pallial line faint, entire. 
21:0733 Genus Amphissa H. & A. Adams, 1853. 
Shell bucciniform, longitudinally ribbed; spire elevated; 
aperture rather wide, enlarging below and terminating in a wide 
anterior sinus; inner lip callous, plicate below; outer lip not 
thickened on the margin, plicate within. 
21:0734 Genus Ancula Loven, 1846. 
Body limaciform, smooth; mantle obsolete, forming an in- 
distinct ridge near the branchiae, bearing 1 or more appendages; 
rhinophores laminate, bearing styliform basal appendages; 
head produced at sides into tentacular processes; odontophore 
with 4 spines in each transverse row, the two next the median 
line large and broad, with inner margin denticulated; central 
spine 0; buccal collar spinous. 
21:0735 Genus Lyonsiella M. Sars, 1872. 
A subgenus of Lyonsia according to Sars, 1868, followed by 
Tryon. 
21:0736 Lyonsiella alaskana Dall, 1894. 
S. W. of Sitka, Alaska, 1659 fathoms; off Catalina Island, 
Cal., 600 fathoms. 
21:0737 Genus Navea Gray, 1851. 
Shell oval, widely gaping anteriorly, close posteriorly; sur- 
fave divided by a subcentral groove; dorsally covered by a co- 
riaceous epidermis, under which is a small transverse posterior 
dorsal valve. 
21:0738 Navea subglobosa Gray, 1851. 
Lobitas to Monterey, Cal. 
21:0739 Genus Norrisia Bayle. 
Shell thick, conoidal, orbicular, covered by an epidermis, 
smooth; wide umbilicus surrounded by callous extension of col- 
umella; outer lip not thickened or sculptured within. 
21:0740 Norrisia norrisii Sby. 1825, sub Trochiscus. 225. 
On kelp, from Monterey bay, Cal. (Berry), to Baja Cali- 
fornia, probably as far south as Magdalena bay? Maximum size 
about 60 mm in diameter, by 30 in height. Rich brown, when 
worn the epidermis shows brick red; tinged with green around 
the umbilious. A showy species. 
21:0741 Genus Panope Menard, 1807. 
Shell equivalve, thick, oblong, gaping at each end; ligament 
external, on prominent ridges; 1 prominent tooth in each valve; 
pallial sinus deep. The name has been usually spelled Panopaea. 
21:0742 Panope generosa Gould, 1856. 1186. 
Puget Sound to San Diego, Cal. Formerly known as Glyci- 
meris g. (357). The king of all the burrowing clams, burrowing 
to a depth of 2 feet or more, and measuring 6 to 8 inches or 
more in length; valves oblong, rather flat, marked with de- 
