THE NAUTILUS. 57 



named shell was generically distinct from Homalogyra and must be 

 labelled Ammonicera Fischeriana. Altogether, I am not quite cer- 

 tain that my shell is really the same as the one referred to by Dr. 

 Vayssiere. It is smaller, horny, with 3 browu lines, has only 3 

 whorls and is but striate, lacking the very remarkable distant and 

 regular sulci somewhat like those of Spirilla Peroni. 



NOTES ON THE GENUS ODONTOSTOMUS. 



BY HENRY A. PILSBRY. 



This group of peculiar land snails is widely spread in southern 

 South America, extending from middle Brazil south well into 

 Patagonia. It is not known to occur in the valley of the Amazon 

 or its tributaries, and is absent in and west of the main chain of the 

 Andes. 



It is allied to Anctus, Tomigems and Anastoma, all Brazilian 

 genera. In conjunction with Mr. E. G. Vanatta I examined the 

 species in the collection of the Academy some time ago, and we 

 agreed that the following subgenera may be distinguished, based 

 mainly upon apical sculpture : 



1. ODONTOSTOMUS Beck (s. str.), type pantagruelinus Moric. 



2. CYCLODONTINA Beck (restricted), type pupoides Spix, inflatus 

 Wagner. 



3. MORICANDIA Pils. & Van. (n. s.-g.), type fusiformis Rang. 



4. SPIXIA Pils. & Van. (n. s.-g.), type spixii Pfr., wagneri Spix. 



5. PLAGIODONTES Doering, type dentatus Wood. 



6. MACRODONTES Swains., type odontostomus Sowb. 



Typical Odontostomus includes the largest and most solid forms, 

 with very large aperture-teeth and folds; all are from eastern 

 Brazil ; Mbricandia is also a Brazilian group. Part of the species^ 

 such as angulatus Wagn., auriscervina Fer., fusiformis Rang, ivilli 

 Dohrn., nasutus Mart., bouvieri Dautz., would naturally be referred, 

 as most of them have been, to Goniostomus ; but their affinities are 

 with 0. bahiensis, pundatissimus, and other dentate species. Spixia 

 has vertical riblets at the apex, as in the Bulimulid group Ortho- 

 toiniwn. Qyclodontina, which we revive in a much restricted sense, 

 is mainly a group of southern Brazil. Plagiodontes is an Argen- 

 tine group, with a host of species, many of which have not been 

 properly defined. The apex is densely wave-striolate. Macrodontes 



