Drawing of general anatomy of Rhiostoma housei specimen CUMZ 3982 from Saraburi Province, Thailand. A female B male. Abbreviations: bc, bursa copulatrix; ; cm, columellar muscle; ct, cephalic tentacle; dg, digestive gland; es, eyespot; f, foot; fc, faeces; int, intestine; lc, lung cavity; mc, mantle collar; od, oviduct; op, operculum; ov, ovary; p, external penis; pg, prostate gland; sg, sperm groove; sn, snout; te, testis; ut, uterus; vd, vas deferens; vg, vaginal groove.