42 
PTEROCYCLOS §.1.2. 
§• 1. 
72 1 . Pt.? ineomptus Sowerby* 
T. late umbilicata, depressa, solida, ruditer striata, opaca, 
sub epidermide fusco- cornea decidua alba; spira parum ele- 
vata, vertice prominulo; anfr. 5 convexi, rapide accrescentes, 
ultimus teres, obsolete angulatus; apertura diagonalis, subcir- 
cularis; perist. simplex, margine columellari incrassato, brevi- 
ter adnato, a supero alatim dilatato sinu profundo sejuncto. — 
Operc.? — Diam. maj. 40, min. 32, alt. 15 mill. (Mus. 
Cuming.) 
Cyclostoma incomptum Sow . Thes. Suppl. N. 183. p. 160*. t. 31 A. 
f. 298. 299.*) 
Ptcrocyclos incompius Pfr. in Zeitschr. f. Mai. 1851. p. 9. 
— — Chemn. ed. II. Cycl. t. 31. f. 1.2. Consp. N. 45. 
Habitat in India? (Sowerby), in Brasilia (Cuming). 
§• 2- 
73 2. Pt. brevis (Lit tins) Ylartyn. 
T. late umbilicata, conoideo-semiglobosa, solida, striatula, 
nitidula, castanea, fulvido-variegata; spira brevis, obtusiuscula ; 
sutura late impressa, marginata; anfr. 5 convexi, ultimus basi 
angulatim in umbilicum infundibuliformem abiens ; apertura 
subcircularis , intus albida; perist. incrassatum, reflexum, 
sup erne ad anfractum penultimum in appendicem triangularem, 
profunde canaliculatam protractum , extus superne tuberculo 
lato, prominente munitum. — Operc. planiusculum , crassum, 
arctispirum, nigricans, anfractibus extimis lamellatim elevatis. 
— Diam. maj. 36, min. 30, alt. 22 mill. Ap. intus 12 mill, 
diam. (Mus. Cuming.) 
Lituus brevis Martyn Fig. of non-described shells t. 28 c. Ed. Chenu 
(Bibl. conch. II.) p. 21. t. 8. f. 2. 
Turbo Petiverianus Wood Suppl. t. 6. f. 2. 
Cyclostoma Petiverianum Gray in Wood suppl. p. 36. 
— — Sow. Spec. f. 97. 98. 
— — Reeve Conch, syst. II. t. 184, f. 15. 
*) T. depresso-suborbiculari , alba, epidermide olivaceo-brunnea induta; 
spira brevi, obtusa; anfr. 4'/ 2 rotundatis, oblique lineis increment! validis 
striatis; sutura distincta; apertura fere circulari, postice prope ultimum an- 
fractum sinuata , extus tuberculam fornicatam formante ; peritremate antice 
incrassato ; umbilico magno. (Sow. 1. c.) 
