456 THE CHICAGO ACADEMY OF SCIENCES. 
Westerlund’s original Latin description is as follows: 
“Testa aperte rimata, elongata, tenuis, fragilis, pellucida, irregu- 
lariter striatula, pallide cornea, spira longa, supra anfractum penulti- 
mum tumidum abrupte angustata, valde contorta, apice acuta; anfr. 
6, perconvexi, sutura profundissima perobliqua disjuncti, superne sub- 
truncati, tumidi, basin versus forte declivi, attenuati; apertura dimid- 
iam testae non attingens, verticalis, subsemicircularis, margine exteriore 
forte arcuato, superne sinuato, medio producto, (columella cum) mar- 
gine columellari substricto, verticali, late reflexo, umbilicum semite- 
gente; columella incisura obliqua sat profunda, plica lata appressa.” 
Westerlund compares his species with Galba traski Tryon but is in 
error as that species belongs to a different group. 
Galba petersi (Dall). Plate XXX, figure 29. 
Lymnea petersi Dati, Alaska Moll., p. 66, pl. 2, fig. 3, 1905.—Purvspry, 
Nautilus, XIX, p. 95, 1905. 
“SHELL: Extremely thin, of five or more tumid rapidly enlarg- 
ing whorls; spire acute, the sutures deep; whorls rounded, the periph- 
ery nearer the preceding suture;. shell of a blackish brown, polished, 
finely, sharply, spirally striate; periostracum brownish, darker at rest- 
ing stages ; aperture oval, a thin wash of callus on the body; pillar very 
thin, gyrate, the gyrations pervious; the outer lip not thickened.” 
Height. Breadth. Aperture length. Breadth. 
16.00 8.00 8.50 5.20 mill. Type. 
Types: Smithsonian Institution, two specimens, No. 180332. 
Type Locarity: Koyukuk River, north of the Yukon in Alaska. 
ANIMAL, JAW, RADULA and GENITALIA: Unknown. 
Rance: Alaska, north of Yukon River; a species of the Yukon- 
ian region. 
RECORDS. 
Koyukuk River, north of the Yukon in Alaska (W. J. Peters). 
GEOLOGICAL RANGE: Unknown. 
Ecotocy: Not recorded. 
Remarks: “This very delicate and pretty species appears to be- 
long to the typical Lymnea in spite of its small size; it has much the 
aspect of a minute L. randolphi, but has more whorls in less than half 
the height and is of quite a different color and without angularity to 
the whorls.” (Dall). . 
Petersi can scarcely belong to the typical Lymnzeas. Its close re- 
semblance to young specimens of Galba randolphi would lead to the 
assumption that its proper position is near that species. A camparison 
