40 
RHIOSTOMA. 
tubulo imperfecto, antice aperto, sinistrorse erecto, rimam co- 
ronante, munito ; umbilico perspective, profundo. — Operculo 
testaceo, multispirato, breviter cylindrico, apice planato, laevi- 
gato, anfractibus arete convolutis, marginibus acute carinatis, 
spatiis intersitis epidermide scabra vestitis , intus profunde 
excavate pelite. — Diam. maj. 21, min. 11, axis 8^/2 mill.“ (B.) 
Rhiostoma Haughtoni Bens, in Ann. and Mag. nat. hist. 3 d. ser. Y. p. 96. 
Pterocyclos Haughioni Reeve Conch, ic. sp. 30. t. 5. 
Habitat ad cavernam Damath^, nen precul ab urbe Meui- 
mein (J. C. Haughten). 
5. Rli. tenerum Henke. 
T. umbilicata, depressa, tenera, cestis preminentibus 
membranaceis munita, pellucida, virenti-cernea; spira medie 
vix elevata ; anfr. 5 cenvexiusculi , ultimus teres, antice bre- 
viter selutus, derse crenulatus, vix carinatus ; umbilicus latus, 
2/5 diametri subaequans; apertura parum ebliqua, subcircu- 
laris, intus leviter margaritacea ; perist. subduplex: internum 
superne breviter incisum, praeterea subadnatum, externum 
brevissime patens, incisuram preminentia levi tubulifermi eb- 
tegens. — Operc. fere Opistheperi, — Diam. maj. 17, min. 
13, alt. 6 mill. Apert, diam. 52/3 mill. (Cell. Nr. 46.) 
Pterocyclos tener Menhe in Malak. Bl. III. 1856. p. 96. 
— — Pfr. Novit. conch. I. p. 90. n. 154. t. 25. f. 13 — 15. 
— — Pfr. Mon. Pneum. Suppl. p. 32. 
— — Reeve Conch, ic. sp. 28. t. 5. 
Rhiostoma tener Bens, in Ann. and Mag. nat. hist. 3 d. ser. V. p. 97. 
Habitat Teuranne Cechinchinae. 
6 . Rli> Repnardii Pfr. 
T. late umbilicata, subdisceidea, selidula, capillacee-striata, 
sericea, elivacee-fulva ; spira parum elevata, vertice minute, 
preminule ; anfr. 5 cenvexi, ultimus teres, juxta suturam tumi- 
dus et leviter sulcatus, antice selutus et supra incisuram 
peristematis tubule brevi curvatule tnunitus; apertura libera, 
fere verticalis, circularis; perist. subincrassatum , breviter ex- 
pansum. — Operc.? — Diam. maj. 15, min. 12 , alt. 7 mill. 
(Cell. Bernardi.) 
Rhiostoma Bernardii Pfr. in Journ. Conch. X. (1862.) p. 45. t. 6. f. 5. 
