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. 
Vayssiére. It is smaller, horny, with 3 brown lines, has only 3 
whorls and is but striate, lacking the very remarkable distant and 
regular sulci somewhat like those of Spirula 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, Tomigerus 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. Oponrostomus Beck (s. str.), type pantagruelinus Moric. 
‘2. CycLopontina Beck (restricted), type pupoides Spiz, inflatus 
Wagner. 
3. Mortcanpra Pils. & Van. (n. s.-g.), type fusiformis Rang. 
4, Sprxia Pils. & Van. (n. s.-g.), type spiwit Pfr., wagneri Spix. 
5. PLAGIODONTES Doering, type dentatus Wood. 
6. Macroponvres 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 ; Moricandia is also a Brazilian group. Part of the species, 
such as angulatus Wagn., auriscervina Fér., fusiformis Rang, willi 
Dohrn., nasutus Mart., bowvieri Dautz., would naturally be referred, 
as most of them have been, to Goniostomus; but their affinities are 
with O. bahiensis, punctatissimus, and other dentate species. Spixia 
has vertical riblets at the apex, as in the Bulimulid group Ortho- 
tomium. Cyclodontina, 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 
