PTEROCYCLOS §. 1. 
41 
Pterocyclos Bernardii Reeve Conch, ic. sp. 23. t. 5, 
Habitat Siam. 
IV. Pterocyclos Benson. 
Pfr. Mon. Pneum. p. 41. Suppl. p. 28. — Animal speciei 
hand nominatae ab A. Adams in Ann. and Mag. nat. hist. 
3 d. ser. VII. 1861. p. 196 descriptum invenies. — Conf. 
W. T. Blanford in Ann. and Mag. nat. hist. Jun. 1864. 
Conspectus specierum. 
A. Aberrantes Nr. 1 — 4. 
B. Normales. 
a. Anfractu ultimo spiraculo munito §. 2. Nr. 5. 
b. Spiraculo nullo 3. Nr. 6 — 17. 
C. Species vix notae .♦....§. 4. Nr. 18 — 19. 
§ 1 . 
1. tenuilabiatus Mete. (Coll. 47. — Reeve t. 1. 220. 
f. 5. — Borneo.) . Pneum. II. p. 18. 
2 . Pt, Pfr. 221, 
T. late umbilicata, subdiscoidea, solida, subtilissime stria- 
tula, sordide flavida unicolor vel in anfractibus superioribus 
castaneo distanter flammulata ; spira vix elevata, vertice corneo 
submucronato ; anfr. 4^/2 convexiusculi , rapide accrescentes, 
ultimus subdepresse rotundatus, non descendens ; apertura fere 
diagonalis, circularis ; perist. duplex : internum porrectum, 
superne leviter incisum, externum la^tere sinistro reflexum, 
dextro sublate patens, superne cucullatim dilatatum et sub- 
deflexum. — Operc. planiusculum , calcareum , marginibus 
anfractuum infundibuliformiter elevatis. — Diam. maj. 18, 
min. 14, alt. 5 mill. Apert, diam. 5 mill. (Coll. Nr. 48.) 
Pterocyclos Labuanensis Pfr. in Proc. Zool. Soc. 1863. 
Habitat in insula Labuan (Hugh Low). 
3 . Pt. liowianus Pfr. 222 
T. late umbilicata, subdiscoidea, tenuiuscula, subtiliter 
striatula, sericina, fulva, flammis saturate castaneis amoene 
