20 CATALOGUE OF PHANEROPNEUMONA. 
Aperostoma Mexicanum, Pfr. in Z. f. M. 1847, p. 104. 
Cyclotus Mexicanus, Gray, Cat. Cycl. p. 9, n. 19; Pfr. Consp. n. 31 ; 
Pneum. Mon. p. 34. 
Hab. Mexico, Papantla (Dr. Schiede). 
32. CYcLOTUS PUSILLUS. B. M. 
Shell suborbicular, thin, slightly striate, nearly smooth, diaphan- 
ous, pale greenish; spire short, raised in the middle, mucronate ; 
whorls 43, convex, the last one deflected, nearly disjoined 
anteriorly, more distinctly striate beneath ; umbilicus broad, 
open; aperture little oblique, nearly circular, white and shining 
inside; peristome continued, rather simple, a little expanded, 
somewhat emarginate at the penult whorl, with the right margin 
forward arcuate. Operc. typical. Height 6, greatest breadth 
11, least br. 9 mill. 
Cyclostoma pusillum, Sow. in Proc. Z. S. 1843, p. 59; Thes. n. 10, 
p. 94, t. 23, £.5,5*; Pfr. Ic. n. 53, p. 59, t. 7, £16, 17. 
Aperostoma pusillum, Pfr. in Z. f. 17. 1847, p. 104. 
Cyclotus pusillus, Gray, Cat. Oycl. p. 9, n.18; Pfr. Consp. n. 33 ; 
Pneum. Mon. p. 34. 
Hab. Philippine Islands, Luzon and Negros (H. Cuming). 
303. CYCLOTUS SCALARIS. 
Shell conoidal, rather solid, obliquely and slightly striate, a little 
shining, horn-coloured yellow; spire raised, stair-like, with the 
apex pointed; suture deep; whorls 43, very much rounded, the 
last one cylindrical, a little disjomed anteriorly ; umbilicus 
narrow, open; aperture oblique, circular, pearly inside; peri- 
stome simple, continued, scarcely expanded on all sides. Opere.? 
Height 63, greatest breadth 9, least br. 7 mill. 
Cyclostoma scalare, Pfr. in Proc. Z. S. 1851; Je. n. 328, t. 41, 
f, 38, 39. 
Cyclotus scalaris, Pfr. Consp. n. 34, p. 50; Pnewm. Mon. p. 35. 
Hab. Philippine Islands. 
§ 3. Peristome double. Cyclotus, Sw. 
34. CycLoTUS HEBRAICUS. B. M. 
Shell rather depressed, nearly orbicular, slightly striate, nearly 
smooth, pale brownish-whitish, often with brown stripes and 
spots above; spire short, rather blunt; whorls 43-5, convex, 
the last one with a chestnut-coloured band below the periphery, 
nearly disjoined anteriorly ; umbilicus broad, quite open; aper- 
ture nearly circular; peristome continued, duplicate; internal 
