26 ZON1T1D.E. 



shaped or sessile spermatbeca or sperm-sac, and conformably with 

 it a very sliort spermatophore of peculiar form with close-set 

 spines, different altogether from that of the MacrocJilammrp. 

 Fig. of animal, PL I. figs. 1 & 2.] 



[^Synopsis of Genera. 



1. Abiophanta. 



With sinistral shells, solid or horny and thin ; left dorsal lohe dis- 

 tinctly separate in two parts. Most species with aculeate laterals 

 in the radula. 



2. NiLGiRiA, Cryptozona, Xestina. 



Dextral shells, mostly solid, and many of large size ; left dorsal 

 lobe undivided, or merely slit. 



3. Indrklla. 



Shell Helicarion-\\\ie, large and thin ; a slit in the left dorsal 

 lobe ; radula with aculeate laterals. 



4. Ravana. 



Shell thin, depressed, smooth, of the Macroclilamys type ; left 

 dorsal lohe divided ; foot truncate. 



5. Eatxadvipia. 



Shell Helicarion-like, few whorls, thin ; animal with both right 

 and left shell-lobes ; foot truncate at extremity ; radula very broad ; 

 teeth very numerous. 



0. EUPLECTA. 



Shell in most cases carinate and closely wound ; lohe above mucous 

 pore more pointed ; dorsal lobe in two distinct parts ; in the male 

 organ a muscular band confines a portion in a looped arrangement.] 



Genus ARIOPHANTA. 



Ariophanta, Desmoulim, Bidl. Soc. Bordeaux, iii, 1829, p. 2.3o, pi. 1, 



tigs, l-o ; G.-A. Moll. Ind. i, 1883, p. 133 : id. t. c. ii, 1898, p. 82 ; 



Blf. Froe. Mai. Soc. iv, 1901, p. 241. 

 Cryptozona, Morch, Jour, de Conch, xx, 1872, p. 334. 

 Xestina, Pfeiffer, JB. mal. Ges. v, 1378, p. 257 ; id. Abh. Ver. Hamb. 



vii, 1883, p. 13 ; couf. v. Mart. Zool Rec. xv, 1880, p. 162. 

 Nilgiria, G.-A. Mol. Ind. i, 1888, p. 253; id. t. c. ii, 1898, p. 77, & 



1899, p. 123. 



Type, A. Icevipes (Miill.). 



Eange. The Indian Peninsula and Ceylon. 



Shell sinistrorse or dextrorse, perforate or umbilicated, of 

 moderate or large size, depressed or globose, striated or decussately 

 striated above, smoother beneath ; peristome thin in general, but 

 not always, the columellar margin more or less reflected. 



Animal with the body wben extended rather broad and de- 

 pressed (broader than that of Macroclilamys). A large mucous 

 pore above the flattened posterior extremity of the foot, without 

 any horn-shaped lobe above (a small blunt lobe is sometimes 

 present) ; peripodial groove well developed, always double ; sole 

 broad, not distinctly divided beneath ; upper surface of body with 

 oblique striae, those on the head and neck anastomosing and 

 forming a distinct tract. The mantle-edge is a narrow band re- 

 flected over the peristome. jSTo shell-lobes ; the two dorsal lobes 



