THE NAUTILUS. 35 



by wider interspaces, finely spirally striated ; after the first three 

 whorls the riblets become closer and slightly arcuately retractive, 

 and the spiral striation obsolete, while the spire is moderately con- 

 stricted in front of the swollen apical whorls, gradually increases 

 toward the tenth where it rapidly enlarges its diameter ; the last two 

 whorls diminish slightly, the base has no carina, but an almost im- 

 perceptible thread continues the sutural line, but does not angulate 

 the almost circular aperture. The lip is slightly expanded and 

 thickened, not produced, and with the throat has a light brownish 

 white color. No lamella is visible in the aperture, but at the back 

 of the last whorl a sharp almost vertical plait surrounds the twisted 

 slender axis, and, in the penultimate whorl only, expands to a flat 

 horizontal lamella, while the twist of the pillar assumes the appear- 

 ance (for about one whorl) of a spiral cord ; the rest of the axis 

 shows only a faint twist, and is very slender, though when broken 

 the section reveals a minute perforation. Two extreme specimens 

 measure : 



No Whorls. Millimeters. 



Adult. Apical. Length. Max. diameter. Aperture diam. 



10 41.5 12.0 8.0 



13 20.0 6.5 



8.5 39.0 14.0 9.5 



13 20.5 7.5 



U. S. Nat. Mus., No. 212319. Also Orcutt collection. 



The shell is about one-third larger than E. (A.) hyalina Pfr., 

 from the same region ; its anterior axial lamella is wider and flatter 

 than that of E. (^4.) liebmanni ; E. (A.) townsendi Pilsbry and 

 Cockerill, is of similar shape, but thinner, and has a much longer 

 lamella. 



Epiphragmophora ^Trichodiscina) verdensis n. sp. 

 Shell of five whorls, whitish, with a brownish, minutely, irregu- 

 larly, obliquely tufted periostracum ; spire depressed with a deep 

 suture and a rounded peripheral keel near the posterior third of the 

 whorl with a marked compression behind it ; nucleus small, minutely 

 pustulate, the pustules being modified as the shell grows, into short 

 elevated ridges along the lines of growth, which bear the tufts of the 

 periostracum ; beside this the entire shell is minutely punctate ; the 



