APPENDIX. 253 



Genus MABILLEA, Bourguignat, 1877. 

 The work in which this Algerian genus and five species thereof 

 are described is unfortunately not accessible to me. It is sup- 

 posed to be closely related to Trigonochlamys (p. 135). 



Genus HELICARION, Fer. 

 H. MINUTUS, Godwin-Austen, p. 182. 

 H. CHRISTIANA, Theobald, p. 176. 



Godwin-Austen has recently referred the above to the group 

 Durgella which will be described in the next volume of the 

 Manual. 



H. BOTTGEBI, Hilber. PI. 60, figs. 73, 74. 



Narrowly umbilicated ; dirty white, under a yellowish-green 

 epidermis ; body-whorl somewhat rugosely striate ; suture with 

 a small bright yellowish band ; columellar callus very thin. 



Diam., 17 mill. China, alt. 3500 metres. 



Subgenus ZONITARION, Pfeffer, 1883. 



Jaw without middle tooth. H. semimernbranaceus, Martens ; 

 H. politissimus, Beck ; H. crenularis, Beck, etc., are members of 

 this group. 



Genus OTOCONCHA, Hutton. 



Shell external, of very few rapidly increasing whorls, all of 

 which are open underneath. Animal limaciform, much too large 

 to withdraw into the shell; mantle rather anterior, covering the 

 shell ; no locomotive disk, nor mucous caudal gland. Jaw with 

 distant ribs. This genus appears to be allied to Peltella from 

 Brazil and the West Indies. 



0. DIMIDIATA, Pfeiffer (p. 181), is the type ; it is one of the group 

 which- 1 have indicated, as approaching Parmarion. 



Genus OTESIA, H. and A. Adams, 1855. 



Shell heliciform, thin, subim perforate, lip simple. Animal 

 similar to Helicarion. Mantle-lobe partly covering the shell. 



This group was placed by Pfeiffer under Nanina, as a section, 

 but its affinities are so decidedly Vitrinoid that I venture to 

 give it a position following Helicarion. Gray described it in 1 855 

 under the name of Vitrinella, already used by Adams for a group 

 of Trochidae. Albers (von Martens) in 1860, called it Medyla. 



