Dentition of Pulmonale Mollushs. 105 



Lingual membrane (PI. VII, fig. K) long and narrow; central teeth tri- 

 cuspid ; laterals bicuspid ; marginals quadrate, irregularly bicuspid, the 

 inner cutting points the larger and bifid. 



Hicropliy§a. 



Micropliysa is put in Helicea by von Martens. M. minuscula 

 (Terr. Moll., V), and circumfirmata, Redf., both belong to Vitri- 

 nea, having aculeate marginal teeth, and jaw of Zonites. M. 

 turbiniformis, Pfr., has a jaw as in Gylindrella, Bulimulus, etc., 

 i. e., with numerous very delicate, distant ribs, giving the ap- 

 pearance of separate plates. It would be put in Goniognatha 

 of Morch, though there are no upper triangular median plates. 

 M. vortex and incrustata (see Terr. Moll., V) have quadrate 

 marginal teeth ; the jaw of incrustata has numerous, crowded, 

 Hat ribs; that of vortex was not observed. 



U!icrojiIiy§a ? c2rcusnfiriain&» 9 Redfield. 



Jaw not observed. 



Lingual membrane long and broad, centrals tricuspid, laterals bicuspid, 

 -cusps long and slender, marginals aculeate. 



From the above description it will appear that this species 

 elongs to the Vitrinea rather than to the Helicea of von Mar- 

 ten's arrangement, in which latter it is classed in "Die Heli- 

 eeen" as a species of the subgenus Microphysa. I leave it here, 

 not knowing what else to do with it. 



Microphysa turbiniformis, Pfr. Jamaica. Mr. Henry Ven- 

 drcyes. 



Jaw (PI. XV, fig. C) so extremely thin and delicate as to fold over on 

 itself along its margin and at its extremities; very light horn-colored, almost 

 transparent ; strongly arched, attenuated towards its obtuse ends ; about 

 forty delicate ribs, such as are found in Oylindrella, serrating either margin 

 on about the centre of the jaw is a curving line of reinforcement, somewhat 

 parallel to the lower margin; the upper margin slightly incurved at its cen- 

 tre ; the ribs at the centre of the upper margin do not run en chevron as do 

 those of Cyiindrella. 



Lingual membrane (PI. VII, fig. L) long and narrow; teeth about 25-1-25. 

 Centrals large in proportion to the laterals, with a subquadrate base of at- 

 tachment; three decided, separated cusps and cutting points; laterals tri- 

 cuspid; marginals low, wide, with both inner and outer cusp bearing an 

 oblique, broad, bifid cutting point. 



