PYRAMIDULA. 45 



P. luseana Paiv. iii, 31. P. pusilla Lwe. iii, 31. 

 P. massoti Bgt. iii, 29. hi/pocrita Dohrn. 



P. micropleuros Pag. iii, 28. servilis Sh. 



P. microstigmsea Silv. P. servaini Bgt. iii, 31. 



P. nemesiana Bgt. iii, 31. P. simoniana Bgt. iii, 3J. 



P. pornse Serv. iii, 31. P. sororcula Ben. iii, 29. 



P. poupillieri Bgt. iii, 29. P. tenuicostata Sh. iii, 28. 



Section Planogyra Morse, 1864. 



Planogyra MORSE, Obs. Terrest. Pulm. Maine, p. 24, type P. 

 asteriscus Mse. 



Shell minute, discoidal, openly umbilicated, the spire flat. Whorls 

 bearing thin, sharp, spaced laminae, parallel to growth-stride. Aper- 

 ture rounded-lunar, lip simple. Type P. asteriscus Morse, pi. 10, 

 figs. 10, 11. 



Jaw slightly arcuate, bluntly rounded at the ends, irregularly 

 vertically wrinkled, the concave margin having a slight median 

 projection. 



Radula consists of 77 transverse rows containing about 13.1.13 

 teeth. Centrals tricuspid. Laterals lacking the entocone. Mar- 

 ginal teeth multi cuspid, the mesocone largest, bifid (pi. 1J, fig. 21, 

 P. asteriscus Morse). 



The radula differs from that of Pyramidula s. sir. only in the 

 development of side cusps on the central tooth, and the shorter 

 mesocone of the same. But one species is known ; it is widely dis- 

 tributed in Canada and northern New England, living in very wet 

 places. 



Morse represents the eye-peduncles of this species as short, thick, 

 and club-shaped (pi. 10, fig. 10); his observation should be checked 

 by an examination of the living animal, as that form of eye stalk 

 is widely different from the other Pyramidula species. 



Section Gonyodiscus Fitzinger, 1833. 



Gonyodiscus FITZ. Syst. Verz. p. 98, proposed for G. perspectivus 

 Fitz.If. solaria Mke. Discus FITZ., Syst. Verz., p. 99 ; proposed 

 for If. rotundata, ruderata, pygmcea, cristallina (not Discus Less. 

 1837, nor of Hald. 1840, nor of Alb. 1850, nor of Campb. 1879).- 

 Patula HELD, in part. Delomphalus AGASSIZ, in CIIARP., Catal. des 

 Moll. Terrest. et Fluv. de la Suisse, p. 12, in Nouv. Mem. de laSoc. 

 Helvetique des Sci. Nat. i, Neuchatel, 1837 ; proposed for H. 

 rotundata, ruderata pygmcea. Eyryomphala (in part) BECK, Index, 



