THE NATURAL HISTORY SURVEY. 225 



Orthurethra. 



Ureter passing directly forward from the kidney toward 

 the anterior of the lung. (Pilsbry.) 



FAMILY PUPID^:. 



Shell: Usually small, multispiral, generally elongated; 

 aperture frequently contracted by internal teeth. 



Animal: Tentacles small or wanting; foot very short, ob- 

 tuse or pointed behind; jaw smooth or finely striated, fre- 

 quently strengthened by the addition of a superior, arched 

 plate, giving it the appearance of a double jaw; dentition re- 

 sembling Helix; central and lateral teeth of same form and 

 size (generally), tricuspid; marginals quadrate, low, wide, den- 

 ticulated. 



GENUS STROBILOPS Pilsbry. 



Strobilops PILSBRY, Proc. Phil. Acad., p. 403, 1892. 



Strobila MORSE, Journ. Portl. Soc^Vol. I, p. 26, figs. 64-67, pi. ii, fig. 12, 



a, b; pi. viii, fig. 68, 1864. (Non Strobila Sars, 1833; Strobilus 



Anton, 1839.) 



Shell: Strongly striated, depressed-conic, umbilicated; 

 aperture lunate; peristome reflected; parietal wall armed with 

 several lamellae which are provided with sharp, spiny projec- 

 tions at regular intervals. 



Animal: Similar to that of Pyramidula. 



Jaw: Long and narrow, arched, ribbed. 



Radula: With numerous teeth similar to those of Pupa. 



Distribution: North America and some of the West Indies. 



87. Strobilops labyrinthica Say, pi. xxx, fig. 14. 



Helix labyrinthica SAY, Journ. Phil. Acad., Vol. I, p. 124, 1817. 

 Strobila morsei DALL, Proc. U. S. Nat. Mus., p. 263, 1885. (Variety.) 

 Strobila strebeli PFEIFFER, Malak. Blatt., Vol. VIII, pi. i, Figs. 5-8. 

 Variety.) 



Shell: Small, depressed-conic, umbilicated; surface cov- 

 ered with numerous heavy, oblique ribs, which are much finer 

 on the base than on the upper surface; the apex is smooth; 

 color brownish horn; whorls six. rounded, regularly increasing 

 in size, the last somewhat globose; sutures well impressed; 

 spire globose-conic or depressed; aperture lunate, a trifle ob- 

 lique; on the parietal wall there are three revolving ribs, two 

 of which nearly or quite reach the aperture while the third 

 lies between these and is more deeply seated; these ribs are 



