CLASS GASTROPODA 
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little anterior and to the right, in an elliptical concentric operculum without 
internal rib, with a large area of adhesion, and an outline in general like 
the operculum of Buccinum. (Dali.) 
Type. Pleurotoma goodei Dali. 
Distribution. Arctic. 
Irenosyrinx pacifica Dali, 1908 
Bulletin , Museum of Comparative Zoology, 43:270; Pi. 12, fig. 3. 
Shell small, delicate, white with a pale yellowish periostracum, with at 
least six whorls beside the (lost) nucleus; spire acute, slender, longer than 
the aperture; suture deep, appressed; whorls gently rounded; apical 
whorls with (on the third about fifteen) very narrow, sharp, threadlike, 
vertical ribs with much wider interspaces, and at the suture numerous, 
irregular, small, retractive folds extending over the fasciole, with wider 
interspaces, nearly twice as many as there are ribs; on the succeeding 
whorls these ribs and folds grow sparser and weaker, so that on the sixth 
whorl ribs, folds, and fasciole are obsolete or absent; on the spire, the axial 
sculpture is crossed by (on the third whorl about eight, on the sixth ten 
or a dozen) fine flat threads with wider interspaces (increasing in inter¬ 
polation), which override the ribs and rise above them but do not form 
nodules at the intersections; these spirals are very uniform, and on the 
last whorl extend forward covering the canal, and are slightly scored by 
the incremental lines; aperture oval, not mature in the specimen, the anal 
sulcus obsolete; pillar and body polished, the surface erased, not callous; 
the pillar is short, gyrate, the axis pervious, but the canal is short, rather 
wide, with no siphonal fasciole; the outer lip only slightly produced, sharp 
and thin in the type specimen. Operculum concentric, pointed in front, 
with an apical nucleus. Long, of (decollate) shell, 23; of last whorl, 15; 
of aperture, 10.5; maximum diameter, 7 mm. (Dali.) 
Type in United States National Museum, No. 122590. Type locality, 
U.S.S. “Albatross” Station 2859, in the Pacific Ocean. 
Range. Southwest of Sitka, Alaska, in 1,569 fathoms. 
Irenosyrinx crebristriata Dali, 1908 
Plate 6, fig. 9 
Bulletin , Museum of Comparative Zoology, 43:272; PI. 13, fig. 10. 
Shell of moderate size, white, covered with a pale periostracum; spire 
acute, a little shorter than the aperture; whorls rounded, six in number 
exclusive of the (lost) nucleus; suture very distinct; axial sculpture none, 
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