LIMN SIDA. 103 
in one piece, arcuated, finely striated with a superior, central 
fibrous projection, recalling the accessory plate in Succinea. 
Radula composed of oblique teeth, the central multicuspid, the 
laterals and marginals serrated and furnished with a small, nar- 
row, special appendage at their superior, outer margin. 
PHYSELLA, Hald., 1842. Shell very small, globular, with short 
and small spire; aperture oval, ample; columella with a well- 
marked plication. P. globosa, Hald. (cili, 15). 
PHYSODON, Hald., 1842. Shell oval-elliptic, rather solid; colu- 
mella toothed. P. microstoma, Hald. (ciii, 16). 
COSTATELLA. Dall. Shell longitudinally, laminately costate. 
Ph. costata, Newe. (ciii, 17). 
APpLEXA, Fleming, 1829. 2 
Syn.—Nauta, Leach, 1831. 
Distr.—25 sp. Europe, North America, Northern Asia. Fossil. 
Kocene of Europe and United States. A. hypnorum, L. (ciii, 19). 
Shell sinistral, thin, elongated, polished ; spire conical, acu- 
minated, with scarcely indented sutures; aperture narrowly 
elongate-oval; columella simple; outer lip sharp. Animal with 
plain mantle-margins. 
MACROPHYSA, Meek, MSS. Spire enormously elongated, body- 
whorl and aperture small. B. columnaris, Desh. (ciii, 20.) Paris 
Basin. 
Butinvus, Adanson, 1757. 
Syn.—Isidora, Ehrenberg, 1831. Diastropha, Gray, 1840. 
Distr.—Mediterranean region, W. Indies, Oceanica. 
Shell like Physa, oval, with very convex whorls and deep 
sutures, apex obtuse ; an umbilical slit ; columella twisted ; peris- 
tome simple. 
Animal resembling Aplexa; jaw in three plates; radula with 
bicuspid central, tricuspid laterals, serrated marginals. 
Puysopsts, Krauss, 1848. 
Distr.—Africa. P. Africana, Krauss (ciil, 21). 
Shell like Physa, but columella truncate below. 
PLATYPHYSA, Fischer, 1883. Last whorl enlarged at the 
shoulder; columella truncate below. P. Prinsepi, Sowerby. 
Eocene ; India. 
PYRGOPHYSA, Crosse, 1879. Spire turreted. Africa, Mada- 
gascar. Probably passes into Isidora, Ehrenb. P. Wahlbergi, 
Krauss. Africa. 
AMERTA, H. Adams, 1861. (Glyptophysa, Crosse, 1870.) Shell 
spirally sculptured, the body-whorl sometimes smooth, not 
glossy. 2 sp. New Caledonia, Australia. P. lirata, Trist. 
(cili, 18). 
