THE - CONCHOLOGISTS’ » EXCHANGE. 
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“ Testa depresso conica, late umbilicato, poly- 
“oyrata. Apertura parva; peristoma reflexum, 
*dentatum.” 
Type: Helix Raffrayi, Tapparone-Canefri. 
Geog. distrib.: I sp.; Western New Guinea. 
XXIX.—Lurystyla, Ancey. 
“ Testa laevigata, solidula, nigra vel brunnea | 
“vel virescens, nigro-cincta, plus minusve ob- 
‘longa vel depressa, summo valde obtuso 
“erosso; habitus fere quorumdam specierum | 
“generis Cochlostyloe simillimus. Umbilicus 
‘‘nullus vel rimiformis. Columella recta, 
‘oblique declivis. Peristoma tenuites expan- 
“sum et incrassatum,”’ 
Types: Helix cerina, Mor.; H. viridis, Desh 
H. cerina shows the above Malgachian 
group, altogether resembling so much the Phil- 
ippinese species of Cochlostyla that H. viridis, 
the first known species of the section was al- 
ways placed by authors in this genus, to be 
much more nearly allied to Helix lancula, Guil- 
laini, etc. (belonging to Ampelita), than may 
be supposed at once. 
Fruticotrochus, Kob., does not appear to differ 
at all from all the described species of Trocho- 
morphodes, Nevill (type: H. acris, Bens. and 
conulus, v, Mart.), excepting in having a larger 
umbilicus. Dr. yon Mollendorff unites both. 
XXX.—Cavicola, Ancey. 
*Testa albido, opaca perforata solidula, con. 
“icoglobosa. Spira elevata, apice acutiuscula, 
“€conica; anfractus saltem 7, regulariter len- 
*teque crescentes, conyexi, sutura profunda, 
** divisi, ultimus tumido-rotundatus, inferne in- 
* flatus, medio filocinctus post medium loeviga- 
“tus, antice non deflexus Apertura lunata, 
“fere recta; peristoma simplex, tenue, basi 
‘‘sinuatum et antice tantisper proyectum, prope 
“ umbilicum parvum minute expansum.” 
Type: Streptaxis (?) cavicola, Gredler. 
Geog. distrib, : The type has been found ina 
caye in Southern Hunan (Central China.) 
I agree with Hende in placing this species 
in Naninidze rather than with Streptaxis. It 
resembles, however, Str. alveus, Dunk, a 
South American species, in a few particulars, 
but is otherwise entirely distinct. As far as 
known the group, to which the latter belongs, is 
not an Asiatic one. Cavicola approaches Si- 
tala and Microcystis. 
XXXI.—#athyaxis, Ancey. 
‘© Testa characteribus nonnullis adeo Ceeliaxi 
“ peraffinis ut sectio hujus generis tantum haberi 
““possit, sed semper integra; columella recta, 
“incranata, plica interna extus non conspicua 
““instructa; umbilicus apertus, profundinimus 
“ (apice testce perspicuo) ; peristoma haud den- 
*“tatum, expansiusculum nec continuum.” 
Type: Coeliaxis Layardi, Ad. & Angas. 
Geog. distrib. : Cape Colony; Albany Coast. 
XXXII.—Aesobia, Ancey. 
“Testa subsolidula fusca, perforata, haud 
“nitens, oblonga, liris spiralibus interruptis, ob- 
‘“‘solete notata, striata. Spira obconica, apice 
‘* papillata, loevi, obtusata. Anfractus convexi, 
‘primi sutura profunda, inferiores profundiore, 
*“quasi excavata separati; ultimus dimidium 
“testce saltem cequans, oblongus. Peristoma 
“subsimplex, ad columellam late expansum.”’ 
Type: Bulimus Helence, Quoy et Gaym. 
Geog. distrib. : St. Helena, 
Concluded. 
Voung @ollectors Corner 
The Fresh Water Mollusks of Fairmount 
Park. 
3Y JOHN FORD. 
Sept., 1887. 
About a dozen genera of fresh water mol- 
lusks, embracing some twenty species, inhabit 
the Schuylkill within the limits of the Park. 
But here, as elsewhere, their presence in large 
numbers at certain points depends not only upon 
a plentiful supply of food, but upon other favor- 
