General anatomy of Rhiostoma haughtoni specimen CUMZ 10048/2 from Dhammatat Cave, Myanmar A right side of male testis and external penis and with enlargement of cephalic area B left side of male shows lung cavity and stomach C right side of female shows ovary and vaginal groove, and with enlargement of cephalic area. Abbreviations: bc, bursa copulatrix; cm, columellar muscle; ct, cephalic tentacle; dg, digestive gland; es, eyespot; f, foot; h, heart; kd, kidney; 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.