384 OPISTHOPORUS. MYCHOPOMA. RHIOSTOMA. SPIRACULUM. 
acutiuscula, violaceo - nigricans ; anfr. 5 convexiusculi, juxta 
suturam planulati et striati , ultimus dilatatus , teres , leviter 
descendens, demum breviter et anguste solutus, spiraculo brevi, 
terminali, juxta anfr actum penultimum munitus; apertura ob- 
liqua, circularis; peristoma simplex, vix expansiusculum, su- 
perne ad spiraculum breviter emarginatum. — Operculum 
cylindricum, arctispirum, supra planulatum, apice leviter im- 
merso, subtus omnino excavatum, latere acute spiraliter sul- 
cato. — Diam. maj. 22, min. 17, altit. 13 mill.; diam. apert. 
7 mill." (M.) 
Pterocyclos Cambodjensis Morelet Series conch. IY. 1875. p. 286. t. 13. f. 1. 
Habitat circa Battambang Cambodjae. 
Obs. Peraffinis videtur 0 . Cochinchinensi Pfr. 
IX. Mychopoma Blanford. 
(P- 45.) 
Genus ex sententia Beddomei Cyathopomatis subgeneri 
Jerdoniae injungendum. 
1. hirsutum Bedd. — Conch. Ind. VII. t. 136. f. 1. 4. 
2. limbiferum Blanf. — Conch. Ind. VII. t. 136. f. 2. 3. 
Obs. His proximum Cyathopoma seticinctum Bedd. 
X. Rhiostoma Benson. 
(P- 46.) 
4. HaughtoniBens. — Pterocyclos Hauahtoni (Rhiostoma) Haul. Sr Theob. 
Conch. Ind. I. t. 5. f. l(h 
XL Spiraculum Pearson. 
(p. 47.) 
— Pterocyclos hispidus Haul. Sf Theob. Conch. Ind. 
1. hispidum Pears. 
I. t. 5. f. 4. 
