PTEROCYCLOS $. 3. 45 
Cyclostoma  angulifera. Soul. in Voy. de la Bonite. Moll. t. 30. f 6—11. 
— anguliferum Pelil »n Journ. Conch. 1850. I p. 43. 
Plerocyclos anguliferus Pfr. im Zeitschr. f. Malak. 1847. p. 111 et 
1851. p. 6. 
— Chemn. ed. II. Cycl yp. 196. t. 94. f. 3— 6. 
Consp. N. 49. 
Habitat in. Cochinchina. 
-6. Pt. temuilabiatus Yetcalfe. "7 
T. late umbilicata, depressa, subdiscoidea, solida, striata 
et undique transverse malleato-impressa, fuscula, strigis casta- 
neis saturatioribus angulosis marmorata; spira plana, subim- 
mersa, vertice subprominulo; anfr. 4'/, modice convexi, cele- 
riter accrescentes, ultimus subdepressus; apertura diagonalis, 
subcircularis; perist. duplex: internum breviter porrectum, 
superne subemarginatum, externum subcontinuum, album, la- 
tere columellari breviter reflexo, dextro dilatato, patente, 
supero juxta anfr. penulümum cucullatim elevato. — Operc.? 
— Diam. maj. 26, min. 21, alt. 6'/, mill. Ap. intus 8 mill. 
diam. (Mus. Metcalf.) 
Cyclostoma  tenuilabiatum Metc. in Proc, Zool. Soc. 1851. 
Pterocyclos tenuilabiatus Pfr. Consp. N. 50. 
Habitat in insula Borneo. 
7. Pt. Albersi Pfr. 18 
T. latissime umbilicata, discoidea, solidula, striatula, sub 
epidermide cornea alba, castaneo marmorata et fascia lata 
nigricante infra medium circumdata; spira medio vix elevata; 
sutura profunde canaliculata; anfr. 5 planiusculi, ultimus antice 
solutus, superne squamoso-carinatus; apertura subcircularis, 
intus albida;  perist. duplex: internum rectum, prominulum, 
expansiusculum, superne profunde incisum, externum subin- 
crassatum, patens, superne in rostrum antrorsum incurvatum, 
liberum, postice in carinam abiens protractum. — Operc. ex- 
tus convexum, spiraliter lamellatum, lamellis inferis spinis 
erectis confertis coronatis, centralibus obsoletis, verticem pla- 
num nudum formantibus. — Diam. maj. 26, min. 22, alt. 9 
mill Ap. 8 mill. diam. (Mus. Cuming. et Albers.) 
Plerocyclos Albersi Pfr. in Zeitschr. f Malak. 1847. p. 151. 
— -— . Chemnmn. ed. II. Cycl p. 197. t. 28. f. 1— 5. Consp. N.51, 
— — Gray Catal. Cycloph. p 12. N, 4. 
Cyclostoma ibersi Petit Journ. Conch, 1850. IL, p. 43, 
Habitat .. . ? 
