30 
PTEROCYCLOS §. 3. 
funde impressa; anfr. 5 convexi, ultimus lente descendens, 
superne alatus , breviter solutus : ala prominentiam elongatam 
angustam ascendentem formante , postice carina obtusa desi- 
nente ; apertura obliqua, subcircularis ; perist. duplex : internum 
porrectum , superne profunde incisum, externum incrassatum, 
superne dilatatum, leviter deflexum ; umbilicus profundiusculus. 
— Operc. pyramidale. — Diam. maj. min. 16, alt. 6 
mill. Ap. diam. 5 j / 2 mill. (Mus. Benson). 
Ptcrocyclos Cingalensis Bens, in Ann. and Mag. N. H. 2d. ser. XI. 
p. 105. 
— — Pfr. in Malak. Bl. 1854. p. 81. 
Habitat ad vicum montanum Monahagalla insulae Ceylon 
(E. L. Layard). 
Obs. Persimilis Pt. Cumingi, umbilico latiore et peristomate distincte 
duplicato discrepans. 
6. Pt. fii fronts Pfr. 
T. umbilicata, discoidea, solida, superne arcuato-striatula, 
nitida, purpurascenti-castanea ; spira plana, vertice subtili, 
lucide castaneo ; sutura alba ; anfr. 6 convexi, ultimus latior, 
peripheria obsolete angulatus, antice descendens et juxta sutu- 
ram prominentiam fornicatam formans, basi violaceus; apertura 
diagonalis , subcircularis ; perist. duplicatum, incrassatum : in- 
ternum superne sulco triangulari interruptum , externum sub- 
patens, superne productum et in prominentiam anfractus ultimi 
transiens. — Operc.? — Diam. maj. 25, min. 21 1 / 2 > alt. 8 mill. 
Ap. diam. 7 mill. (Mus. Cuming.) 
Pterocyclos bifrons Pfr. in Proc. Zool. Soc. 1855. p. 117. 
Habitat in insula Ceylon. 
Obs. Differt a Pt. Cumingi praeter colorem anfractu ultimo latiore, 
umbilico angustiore, peristomate duplicato. 
* 
7. Tiilabiatus Hesss. ( Gray Phan. p. 31. — Ad. Gen. 
p. 277.) 
8. Alberii Ffr. ( Gray Phan. p. 28. — Ad. Gen. 
p.277, — Variat unicolor pallide corneo-lutescens. — 
Hab. ad Teria Ghat, montium Khasia dictorum por- 
tam : Bens, in Ann. and Mag. 1857. XIX.) . . . 
9. angift1ifei*si!4 (Coll. 38. — Gray Phan. 
p. 27. — Ad. Gen. p. 277. — Cycloius? angulife- 
rus M. E. Gray Fig. Moll. Anim. t. 303. f. 9. [ex 
Soul.] — • Cyclostoma angulifera Soul, Voy. Bonite. 
Zool. II. p. 530.) 
10. rupestris Bens. (Coll. 39. — Ch. ed. nov. p. 231. 
— Gray Phan. p. 29. — Ad. Gen. p. 277. t. 85. 
f. 3. — Steganotoma yicta Trosch. — Stcgan. rupe * 
stris Morch Yold. p. 41. n. 822.) 
Mon. p. 49. 
- 45. 
- 44. 
- 46 . 
