ALCADIA. 
409 
obtusum, extrorsum prominentem terminata, retrorsum in cul- 
lum latum, semicircularem abiens ; perist. incrassatum, reflexum, 
luteum, margine supero sinuoso, basali incisura brevi a colu- 
mella separato. — Operc. ? — Diam. maj. 16, min. 13, alt. 
10‘/ 2 mill. (Mus. Cuming.) 
Helicina citrinolabris Adams Cojitrib. to Conch. N. 1. p. 14. *) 
/?. Minor, testa minus depressa, peristomate albo. (Coll. N. 81.) 
Helicina albolabris Adams Contrib. to Conch. N. 1. p. 13. **) 
Habitat in insula Jamaica. 
9. A* Holland! Adams. 720 
T. globoso - conoiclea, tenuiuscula, saturate castanea, sub- 
decussata, sub lente pustulosa; spira late conoidea, acutius- 
cula; anfr. 5 parum convexi, celeriter accrescentes , ultimus 
antice subdescendens ; apertura diagonalis , triangulari-semilu- 
naris; columella brevis, in dentem antrorsum arcuatum desi- 
nens, fissura brevi a perist. simplice, acuto, expanso separata; 
callus basalis semicircularis, nitidus. - Operc. solidum, semio- 
vale, basi acute angulatum, cinerascens. — Diam. maj. 12, 
min. 10, alt. 8'/ 2 mill- (Coll. Nr. 82.) 
Helicina Hollandi Adams Contrib. to Conch. N. 1. p. 13. ***) 
— — Chemn. ed. II. t. 10. f. 18—20. 
Habitat in insula Jamaica. 
10. A. succinea Pfr. 72 1 
T. orbiculato-conoidea, tenuis, sub lente granulata, pellu- 
cida, nitida, rubello-succinea, seriebus pilorum nigrorum (praeter 
anfr. ultimum obsoletis) munita; spira breviter conoidea, acu- 
*) Shell brown or lemon yellow, very solid, outer lip very thick and 
always lemon yellow ; in other characters like H. albolabris , of which it 
may possibly be a variety with a greater divergence. The epidermis is very 
finely but not densely hirsute. — Mean divergence 123°; length 0,39 ; great- 
est breadth 0,67; least breadth 0,53 inch. (Adams 1. c.) 
**) Shell with a notch like that of H. maxima , but the notch is rather 
large proportionally ; in other respects similar to H. Brownii , but the 
whorls are less convex , and the last one much depressed , and the shell 
more solid, with a greater divergence. — Mean divergence 110°; length 
0,39 ; greatest breadth 0,64 ; least breadth 0,5 inch. (Adams 1. c.) 
***) Species similar to H. Brownii , but the shell is much smaller 
and thinner; it is chiefly distinguished by the incision being only half as 
deep , and by the produced columella , which has no impressed line nor 
groove, although slightly raised at the margins. — Mean divergence 105°; 
length 0,23; greatest breadth 0,41; least breadth 0,32 inch. (Adams 1. c.) 
