196 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



Achatina gracillima, PFEIFFER in WIEGM. Arch., 1839, I. 352. BINNEY, Terr. 



Moll., II. 293, PI. LIII. Fig. 3. 

 Biilimus gracillimus, PFEIFFEE, Symb., III. 54 ; Mon. Hel. Viv., II. 160. - 



KEEVE, Con. Icon., 594. W. G. BINNEY, Terr. Moll., IV. 134. 

 Achatina striato-costata, D'0-RBIGNY, Moll. Cub., I. 176, PI. XI. Figs. 19-21? 

 Mdanidla gracillima, TRYON, Am. Journ. Conch., III. p. 301 (1868). 

 Stenogyra gracillima, W. G. BINN., L. & Fr.-W. Sh., I. 232 (1869). 



Cuba, St. Thomas ; also Bahamas ; introduced into the Florida Subregion, 

 having been found on the Keys, and on the mainland near the Miami River. 

 Animal not observed. 



EXTRALIMITAL SPECIES OF SxENOGYRA. 



Slenogyra (Subulina) odona, CHEMNITZ, lias been found in greenhouses, having 

 been introduced on plants. 



PUPA, DR. 



Animal heliciform (Vol. III. PI. LXXII. Fig. 1), blunt before, tapering be- 

 hind ; mantle posterior, thin, protected by a shell ; respiratory and anal orifices 

 on the right side of the mantle, under the peristome of the shell ; generative 

 orifice behind the right eye-peduncle ; no caudal mucus pore or locomotive disk. 



Shell cylindrical, ovate or buliform, rimate or perforate ; last whorl propor- 

 tionally small ; aperture semioval or subrotund, generally furnished with enter- 

 ing, fold-like denticles ; peristome expanded or subsimple, margins equal, sub- 

 parallel, distant, usually connected with a callous lamina. 



The genus is widely distributed. 



Most of the species are so small that it requires much care and no little skill 

 to find them. Some are found in forests, under decaying leaves or fragments 

 of dead branches, lying on the ground, or in the crevices of bark, or about de- 

 caying stumps and logs ; some are found in plats of moss, others under stones, 

 sticks, etc., in the open fields; and many at the margins of brooks, pools, and 

 ponds, under chips, or crawling up the stems of plants, and seem to be incapa- 

 ble of existing unless abundantly supplied with moisture, seeming to be aquatic 

 rather than terrestrial in their habits. They feed on decaying vegetable mat- 

 ter, keeping themselves in the shade, and adhering closely to the objects on 

 which they rest when in repose. In the winter they bury themselves under the 

 leaves or in the earth. 



Animal small, about twice as long as broad, wide and square in front, slightly 

 tapering and obtusely rounded posteriorly ; beneath, the head is separated 

 from the foot by a transverse line ; the cephalic portion is transverse, more or 

 less lobed in front ; the base of foot is long-oval, truncate in front. Tentacles 

 short and sometimes reduced to a minute tubercle. The viscera are remark- 

 able for their great length. 



I have personally examined the jaw and lingual membrane in only two 

 species, P.fallax (PI. IV. Fig. T) and P. rupicola (PI. IV. Fig. S). For in- 



