130 
MOLLUSCA. 
Genital apparatus ordinarily with various appendages, as a flagellum on the penis, 
one, two, or numerous glandule mucosex, and a thick-walled bag (dart-sac) producing 
a calcareous dart. 
Without doubt, this genus, as it is here circumscribed, must, eventually, be still 
more dismembered. Solaropsis and Oxychona will probably prove to be generically 
distinct ; but as their anatomy is very little known as yet, I prefer for the present to 
treat them as subgenera of Helix. 
TABLE OF SUBGENERA. 
mida, umbilicata. 
variegata. 
laris, lunata, 
breviter reflexa. 
| 
Nomen. Forma. Sculptura. Coloratio. Apertura. Magnitudo. Patria. 
| mm. 
_ ACANTHINULA...... subglobosa, perfo- | rugulosa vel cornea vel fusca, simplex, recta. 12-3 Florida, and E. 
rata. striolata. unicolor. Mexico—Nicaragua. 
| Varuomta seenveces depressa, umbili- | sublevis (vel albida. circularis, re- 3 Centr. Guatemala 
cata. costulata), flexa. (cireumboreal). 
| 'TrrcHoprscrwa ee * granulata et fusco-cornea, ple- | perobliqua, leviter| 8-17(80) | E. and Centr. 
| pilosa. rumque fasciata. reflexa. Mexico-S. Costa 
l. Rica. 
| PRaTIcoLELLA ...| globosa, perforata. | sublzevis. fulva vel albida, subverticalis, re- 8-15 Texas, and N. 
seepius fasciata. flexa. Mexico-Nicaragua. 
|__— 
| ARIONTA........004. ” striatula vel rugu-| flavescens, fusco-uni-| sat obliqua, re- 12-19 N., N.W., and E. | 
| loso-punctata. fasciata. flexa. Mexico. | 
— —| 
| PoMATIA............ globosa, perforatione| striata. fasciata. subverticalis, am- 30-38 Centr. Mexico (in- | 
obtecta. pla, reflexa. troduced) (Europe 
| &e.). 
| LysInok ............ globosa vel depresse| granulato-pilosa. ” ” 26-70 N. Mexico-Salvador 
| globosa, perforata. and Mosquito 
| Coast. 
| OXYCHONA «0.0.2... trochiformis vel levis, nitida. alhida, fusco-fasciata| subhorizontalis, 15-38 N. Guatemala-S.E. 
lenticularis. vel guttata, late reflexa. Costa Rica. 
SoLAROPSIS......... depressa, infra tu- | granulata, flavescens, rufo- subperpendicu- 20 (60) 8.H. Costa Rica, 
Subgen. AcanTHINULA, Beck. 
Shell small, thin, unicolorous, horny, rather globose ; umbilicus small ; peristome thin, 
straight, or a little reflexed. 
Under this head may provisionally be included, until the anatomical characters are 
known, several small shells which differ from Guppya by the surface not being so 
smooth and glossy, and from Patula by the very small umbilicus. 
In general appear- 
ance they more or less approach the European Helix (Acanthinula) aculeata, Miill., in 
which the presence of a dart and a flagellum has been stated by A. Lehmann, Die 
lebend. Schnecken u. Muscheln Stettins, 1873, t. 11. fig. 32, 
