88 THE NAUTILUS. 
Brazilian and Mexican species, and by the kindness of Professor 
Gwatkin, of Cambridge, England, who supplied a mounted prepa- 
ration, I was enabled to figure the jaw and teeth of Helix bifasci- 
ata, the type of Oxychona, and up to this time, the only species of 
the group to be dissected. At that time I called attention tothe 
resemblance in dentition between Oxychona, Papuina, Polymita and 
other arboreal Helices, ending with an allusion to the teeth of 
Otostomus (now known as Drymeus aurisleporis). Recently while 
studying the aurisleporis group of Bulimi, I was again struck with 
the extreme resemblance of their radule to that of Oxychona.. Now, 
since my former examination of Oxychona, the study of Bulimulid 
groups has been revolutionized by the discovery of extremely char- 
acteristic generic and subgeneric characters in the sculpture of the 
nepionic shell, as the part formed within the egg is called ; so that 
I at once examined the apex of the Oxychona. The lens revealed in 
H. bifasciata and the other Brazilian species, the minutely “ grated” 
sculpture of Drymeus! This combination of the very characteristic 
and peculiar nepionic sculpture of Drymeus* with the equally char- 
acteristic dentition, conclusively show that Oxychona is a Drymeus 
masquerading as a Helix. The Central American and Mexican 
species referred to Oxychona have smooth apices, very different from 
the Brazilian group. There can be little doubt that these are true 
Helicidze; and as they must now be cut adrift from Ozychona, I 
propose to reinstate for their reception the group name Leptarionta 
Crosse & Fischer, based upon Helia bicincta Pfr. This willstand as 
a genus, and may still be left in my group Belogona euadenia (dart 
bearers with true glands), next to Lysinoe, until more is known of 
the soft parts. Atleast one of thespecies, L. trigonostoma, is known 
to have a serrate keel on the tail like Lysinoe. 
Figures of the apices of Oxychona and its Bulimulid allies may 
be found in the current volume of the Manual of Conchology. The 
evidence supplied by Semper, Hedley and myself that true Helices 
often appear disguised as Bulimi, now finds its counterpart in the 
Bulimulide, in such Helicoid species as Bulimulus eremothawma 
Pils., and that worst cheat of all, Drymeus ( Oxychona) bifasciatns 
Burrow. 
4 Drymeus includes not only the Aurisleporis group and the flaring lipped 
Bulimuli like serperastus, but also ‘*‘ Bulimulus” dormani and multilineatus 
among Floridian species, either of which, if unworn, will show the apical 
sculpture alluded to under a sufficiently strong lens. See Nautizus, IX p, 114. 
