Rhynchonema Cobb 1920

Genus Rhynchonema Cobb, 1920 Diagnosis (Emended from Fonseca & Bezerra 2014): Xyalidae. Cuticle coarsely striated, vacuoles may be present. Amphideal fovea placed over or very close to the end of pharyngostome. Its shape is circular or oval and an amphideal plate may be present (amphideal plate was used to characterize the cuticle annules without division which accommodates the entire amphideal fovea). In some species, amphideal fovea of the males is different to that of the females (oval x circular). The buccal cavity is long and tubular, divided in two parts: cheilostome, short anterior chamber at the level of cephalic setae; pharyngostome, a narrow tubular part extending along the cervical region. Males with two testes. Spicules can be symmetrical or asymmetrical. Gubernaculum is present in most species and normally with apophysis. Precloacal supplements present or absent, when present, they are papilliform (not always easy to see). Females with reproductive system monodelphic prodelphic the left of intestine. Tail conical. Type species: Rhynchonema cinctum Cobb, 1920. List of valid species 1. Rhynchonema amakusanum Aryuthaka, 1989 (Oniike, Shimoshima Island, Japan) 2. Rhynchonema ambianorum Boucher, 1974 (Eastern English Channel, Bay of Somme) 3. Rhynchonema annulatum Tauheed & Ahmad, 2017 (Odisha, India) 4. Rhynchonema brevituba Gerlach, 1953 (Mediterranean Sea, San Rossore, Pisa, Italy) 5. Rhynchonema cemae Bezerra, Smol & Vincx, 2014 (Olinda’s Isthmus, Pernambuco, Brazil) 6. Rhynchonema ceramotos Boucher, 1974 (Eastern English Channel, Bay of Somme) 7. Rhynchonema chiloense Lorenzen, 1975 (Quellon Viejo, SW coast of Chiloé Island, Southern Chile) 8. Rhynchonema cinctum Cobb, 1920 (Salavery, Peru) 9. Rhynchonema collare Nicholas & Stewart, 1995 (Rosedale beach, New South Wales, Australia) 10. Rhynchonema deconincki Vitiello, 1967 (L’Aber, Roscoff, France) 11. Rhynchonema dighaensis Datta, Navarrete & Mohapatra, 2015 (Digha, India) 12. Rhynchonema dispar Gourbault, 1982 (La Grande Anse, Deshaies, Basse-Terre, Guadeloupe) 13. Rhynchonema falciferum Boucher, 1974 (Bay of Morlaix, (western English Channel) and Bay of Somme Eastern English Channel) 14. Rhynchonema fossum Lorenzen, 1975 (Santa Marta, Atlantic coast of Columbia) 15. Rhynchonema gerlachi Vitiello, 1967 (Europa Island, Mozambique Channel, Madagascar) 16. Rhynchonema hirsutum Hopper, 1961 (Alabama Coast line, Gulf of Mexico) 17. Rhynchonema impar Lorenzen, 1975 (Santa Marta, Atlantic coast of Columbia, Southern Chile) 18. Rhynchonema kikuchii Aryuthaka, 1989 (Amakusa Shimoshima Island, Japan) 19. Rhynchonema longituba Gerlach, 1953 (Mediterranean Sea, Pisa, Italy) 20. Rhynchonema lorenzeni Tauheed & Ahmad, 2017 (Bay of Bengal, West Bengal, India) 21. Rhynchonema lyngei (Allgén, 1940) Gerlach, 1953 (Tvärminne,Western Gulf of Finland, Finland) 22. Rhynchonema megamphidum Boucher, 1974 (Pierres Noires, Bay of Morlaix (western English Channel), North Britain) 23. Rhynchonema moorea Boucher, 1974 (Barrier reefs of Lagoon Moorea, French Polynesia, Society Islands, Central Pacific) 24. Rhynchonema ornatum Lorenzen, 1975 (Salamanca Island (Santa Marta), Columbia) 25. Rhynchonema pulchrum Fadeeva & Karpova, 2024 (Vostok Bay, Sea of Japan) 26. Rhynchonema quemer Boucher, 1974 (Bay of Somme, Eastern English Channel) 27. Rhynchonema scutatum Lorenzen, 1972 (Northwest of Helgoland, North Sea) 28. Rhynchonema semiserratum Lorenzen, 1975 (Pelluco at Puerto Montt, Southern Chile) 29. Rhynchonema separatum Lorenzen, 1975 (Quellon Viejo, SW coast of Chiloe Island, Southern Chile) 30. Rhynchonema siddiqii Tauheed & Ahmad, 2017 (Thiruvananthapuram, India) 31. Rhynchonema sieverti Gourbault, 1982 (Le Gosier, Grande-Terre, Guadeloupe) 32. Rhynchonema subsetosum Murphy, 1964 (Governor Patterson Memorial State Park, Oregon, North Pacific Coast) 33. Rhynchonema tomakinense Nicholas & Stewart, 1995 (Tomakin beach, New South Wales, Australia) 34. Rhynchonema tremendum Lorenzen, 1975 (Quellon Viejo, SW coast of Chiloé Island, Southern Chile) 35. Rhynchonema veronicae Bezerra, Smol & Vincx, 2014 (Olinda’s Isthmus, Pernambuco, Brazil) 36. Rhynchonema xiamenensis Huang & Liu, 2002 (Xiamen Island, Fujian, China) 37. Rhynchonema laminam sp. nov. 38. Rhynchonema potiguar sp. nov. 39. Rhynchonema cleoae sp. nov.