116 PLANISPIRA. 



These shells are characterized by the deeply descending whorl at 

 the aperture, and the strongly converging ends of the lip. The 

 anatomy is in essential agreement with either Chloritis or Plani- 

 spira, although the strong ribbing of the jaw is most like the former 

 group. On the other hand, the general form of the shell, the deep 

 descent of the last whorl to the very oblique aperture, and the 

 system of coloring, agree more nearly with Planispira. The sculp- 

 ture of the shell varies considerably in the different species. The 

 more typical, such as falladosa, nilagirica, proxima, as well as vittata 

 exhibit an apparently smooth apex ; but propinqua, tanqueryi and 

 a few others, show an excessively fine quincuucial puncticulation of 

 the apical whorls, such as occurs in Chloritis, in combination with 

 the characteristic shell contour of Trachia. Until we know by the 

 examination of numerous species, how and to what extent the char- 

 acters of jaw and genitalia are correllated with the above-men- 

 tioned shell structures, no consistent zoologist will be justified in 

 drawing rigid lines of demarcation between the Chloritis and Plan- 

 spiras of southeastern Asia. It is better to frankly recognize the 

 fact that in this area the two groups are represented by some forms 

 which, so far as shell characters show, are undifferentiated or separ- 

 ated by feeble characters only. 



(Group of P.fallaciosa). 



P. albicostis Pfr., iv, 65. P. helferi Bens., iv, 63. 



P. asperella Pfr., iv, 62. P. nilagirica Pfr., iv, 65. 



granifera Bens. P. penangensis Stol., iv, 63. 



P. atkinsoni Theob., iv, 56 P. proxima Fer., iv, 63. 



P. contracta Hutt., iv, 65. P. ruginosa Fer., iv, 63. 

 P. delibrata Bens., iv, 64. v. crassicostata Bens., iv, 64. 



procumbens Old. P. sordid a Pfr., iv, 65. 



v. fasciata G.-A., iv, 64. P. vittata Miill., iv, 120. 



v. khasiensis Nev., iv, 64. zonula Wood. 



P. fallaciosa Fer., iv, 64. v. spinolse Villa, iv, 120. 



P. footei Stol., iv, 64. 



( Group of P. gabata). 



P. trochalia Bens., vii, 88. P. pilisparsa Mart., viii, 192. 



hiysbyi Tryon. P. smithii Bock, iv, 57. 



P. gabata Old., iv, 57. P. wrayi Morg., vii, 86. 



v. merguiensis Phil. P. hardouini Morg., vii, 86. 



