198 ACANTHOPUPA. 



2. Zo6genetes( ?) HARPULA (Eeiiih.). 



Shell dextral, minute, conic, unibilicate, corneous. Four 

 cylindric, regularly increasing whorls, under the lens deli- 

 cately striate, silky, the last two-fifths of the length, rounded, 

 not descending. Suture deep. Aperture oval, vertical ; peri- 

 stome unexpandecl, acute, the columellar margin broadly re- 

 flected. Length 1.5, width 1.25 mm. (Reinh.). 



Japan: Tokyo, Kanda (Dr. Gottsche). 



Helix (Acanthinula) harpula Reinhardt, SB. Ges. Naturf. 

 Freunde Berlin, 1886, p. 115. 



The shell is a diminutive picture of the northern H. harpa 

 Say, except that the prominent, regular epidermal ribs of the 

 latter are wanting. Isolated ones among the stria? visible 

 under the lens show a tendency to stand out as weak ribs, but 

 without any regularity (Reinh.). 



An unfigured species, which from the description appears 

 to resemble Pupisoma; with that genus the type should be 

 compared. 



Genus ACANTHOPUPA Wenz. 



"Shell elongate-ovate with blunt embryonic end, narrowly 

 unibilicate; with the exception of the first, all whorls have 

 oblique, widely-spaced, transverse ribs. Aperture with simple, 

 sharp margins and reflected columellar margin." Type Aetni- 

 thopupa joossi Wenz, pi. 32, figs. 19, 20. 



"This genus differs primarily from Acanthinula by the 

 elongate form of the shell, which is much higher than wide." 



Acanthopupa joossi Wenz (pi. 32, figs. 19, 20), Jahrb. 

 Nassau. Ver. Nat., 67th Jahrg., 1914, p. 103, pi. 7, f. 29. 

 Upper Oligocene, Chattien: Landschneckenkalk, Hochheim- 

 Florsheim. 



It is regarded by Wenz as probably of great significance in 

 the phylogeny of Acanthinula, the shell-form uniting that 

 genus to Vertigo. Unless much earlier Acanthopupa? are 

 found, it appears uncertain whether the genus is ancestral to 

 Acanthinula or a secondarily pupoid derivative thereof. Acan- 

 thinula appeared in the Paheocene, long before the advent of 

 Acanthopupa as now known. 



