RIIIOSTOMA. 39 



castaneis vuriegata ; spira parum elevata, verticc minuto, corneo; 

 anfr. 5 depresso-rotundati, ultimiis infra peripheriam castaneo- 

 unifasciatus , antice longe solutus et deflexus, a sutura ad 

 tubulum carinatus, ante tubulum introrsum apertum , extus 

 longe recurvatum leviter incisus ; apertura obliqua, circularis ; 

 perist. subduplicatum, album , margine sinistro incrassatum, 

 dextro expanso, plane patente. — Operc. cyathiforme, extus 

 phmum , anguste spiratura , marginibus anfractuum elevatis, 

 membranosis. — Diam. maj. 35, min. 25, ah. 12 — 14 milh 

 Apert. diara. 11-12 mill. (Mus. Cuming et Coll. Nr. 45.) 



Rhiostoma Haincsi Pfr. in Pioc. Zool. Soc. 1862. p. 115. t. 12. f. 8. 



Pterocyclos Haincsii Reei^e Conch. ic. sp 19. t. 4. 

 Habitat Camboja (Mouhot). 



3. Rh. simiilivilabre Pfr. 216. 



T. late umbiHcata, depressa, soHdula, leviter et confertis- 

 sime striatula, sub epidermide nitida lutescens , elegantissime 

 et subtiUter castaneo-flammulata ; spira breviter conoidea, vertice 

 minuto, obtusiusculo ; anfr. 5 depresso-rotundati, uhiraus infra 

 peripheriam castaneo-unifasciatus , antice sublonge solutus et 

 deflexus, a sutura tisque ad tubuhim recurvatum carinatus; 

 apertura diagonaUs, subcircularis, intus coerulescenti-margari- 

 tacea; perist. simplex , tenue, ante tubulum leviter incisum, 

 undique vix expansiusculura. — Operc. praecedentis, angu.stius 

 spiratum. — Diara. maj. 27^2, min. I91/2, alt. 10 mill. Apert. 

 diam. 8% raill. (Mus Curaing.) 



Rhwstoma simplicdabre Pfr. in Proc. Zool. Soc. 1862. p. 115. t. 12. f. 7. 

 Ptcrocijclos simplic ilaf/1'is Reeve Conch. ic. sp. 20. t. 4. 



Habitat Camboja (Mouhot). 



4. Rla. Haiiglitoiii Beiison. f 217. 



„T. late umbiHcata, convexo-depressa, soHdiuscula, obHque 

 scabre striatula, superne castanea, subtus albida, fascia angusta 

 mediana saturatiori, utrinque angulato-marmorata, ornata; spira 

 depresso-conoidea, apice prominulo, obtusiusculo ; sutura im- 

 pressa ; anfr. 5, convexiuscuHs, uhimo cyHndrico, antice longe 

 soluto, lateraliter descendente, superne carina obtusa a sutura 

 usque ad tubulum mai-ginalem decurrente raunito; apertura 

 Hbera, obliqua, diagonali, circulari, peristoraate subdupHci, 

 extus incrassato, reflexiusculo, superne ad sinistram inciso. 



