CLASS GASTROPODA 
135 
keel, which is smaller, and in the subsequent whorls the suture is not 
appressed but distinct; spiral sculpture of on the first two whorls a strong 
peripheral cord and one thread at the suture, on the third whorl three 
threads in front of the cord, on the remainder four, on the last whorl 
the peripheral cord is not prominent but from the anal fasciole to the 
canal are about 16 strong threads with wider interspaces and an occa¬ 
sional intercalary smaller thread; they do not nodulate when they cross 
the ribs; on the canal are numerous small close-set threads; the anal 
fasciole is without spiral sculpture; axial sculpture of (on the last whorl, 
13) strong rounded ribs not continuous up the spire and obsolete on the 
base but prominent and arcuate over the fasciole, reaching the preceding 
suture which they undulate; aperture rather narrow, the anal fasciole 
at the suture, shallow and wide, the outer lip thin, moderately produced, 
the inner lip smooth, erased; pillar short, straight, attenuated in front, 
canal short but distinct. Height of shell, 13; of last whorl, 8; diameter, 
5 mm. (Dali.) 
Type in United States National Museum, No. 208560. Type locality, 
Granite Cove, Port Althorp, Alaska. 
Range. Known only from type locality. 
Mangilia althorpi Dali, 1919 
Proceedings of the United States National Museum, 56 :68; PI. 19, fig. 9. 
Shell small, waxen white, superficially resembling M. granitica, but 
differing in the following particulars: It has one rib less; the two promi¬ 
nent spiral cords on the early whorls are strongly nodulous when they 
cross the ribs, especially the posterior cord, even on the last whorl; the 
spiral sculpture on the last whorl in front of the fasciole comprises 10 
strong fiattish cords, separated by very sharp, narrow grooves, with no 
spiral sculpture on the back of the canal, which is distinctly shorter; 
aperture relatively shorter and wider; the nucleus apparently similar but 
eroded, the number of whorls is the same but the shell is shorter. Height 
of shell, 11.5; of last whorl, 6.5; diameter, 4.5 mm. (Dali.) 
Type in United States National Museum, No. 208560a. Type locality, 
Station 1413, Granite Cove, Port Althorp, Alaska. 
Range. Known only from type locality. 
Mangilia sculpturata Dali, 1886 
Proceedings of the United States National Museum, 9 :299; PI. 4, fig. 7. 
Shell seven-whorled, turreted, white, with strong waxen yellow epi¬ 
dermis ; thin, with strong sculpture; transverse sculpture of, on the last 
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