1. Anchylosed neurohooks starting between chaetigers 4-7, continued throughout the body................................................................................................................................... 2
— Anchylosed neurohooks starting from chaetiger 14, or from posterior chaetigers...... 15
2. Body with sediment particles...................................................................................... 3
— Body almost without sediment particles, with very few, sparse sediment grains, or without sediment grains; anterior chaetigers sometimes with very few sediment particles, or with a thin, dark-brown or blackish crust........................................................................... 6
3. Sediment particles present over the dorsal and ventral surfaces................................... 4
— Sediment particles concentrated dorsally, sometimes extending laterally..................... 7
4. Sediment grains small, very abundant........................................................................ 5
— Sediment grains large; anterior chaetigers without dorsal tubercles or notopodial lobes; first neurohooks from chaetiger 5............................................................................... 9
5. Anterior chaetigers with dorsal tubercles but no notopodial lobes; first neurohooks from chaetiger 7.............................................. T. grandis (Blanchard in Gay, 1849) n. comb.
— Anterior chaetigers without dorsal tubercles or notopodial lobes; first neurohooks from chaetiger 5.................................................................... T. ehlersi (Day, 1973) n. comb.
6. Neurohooks bifid; sediment particles mostly black.... T. rigida (Caullery, 1944) n. comb.
— Neurohooks entire; sediment particles mostly white................... Trophoniella sp. Brazil
7. Tunic with fine particles, difficult to be detected; notopodia with 6-7 chaetae per bundle; first neurohooks in chaetigers 5-6.......................................................... T. lindae n. sp.
— Tunic with larger particles, easily noticed individually................................................ 8
8. Body wall pale or pinkish; few notochaetae (4-5) per bundle; anchylosed neurohooks from chaetigers 4-5........................................... T. americana (Monro, 1928) n. comb.
— Body wall grayish; abundant notochaetae (8-10) per bundle; anchylosed neurohooks from chaetigers 5-7........................ T. tumbensis (Hartmann-Schröder, 1962) n. comb.
9. Some neurohooks bidentate; 7-9 notochaetae per bundle........................................................................................................................... T. incerta (Augener, 1918) n. comb.
— All neurohooks entire, sometimes eroded................................................................. 10
10. Body with few sediment particles over anterior chaetigers........................................ 11
— Body without sediment particles.............................................................................. 12
11. Body dark pink, finely speckled with red spots, rarely pale; cephalic cage twice as long as body width; 6-8 notochaetae per bundle................................................ T. reishi n. sp.
— Body solid brown; cephalic cage 1.0-1.5 times as long as body width; 7-8 notochaetae per bundle................................... T. rudis (Grube & Müller in Grube, 1877) n. comb.
12. Parapodial papillae digitate or slightly capitate; notochaetae with regular articulation..... 13
— Parapodial papillae markedly capitate (distally expanded); notochaetae with irregular articulation, several short articles followed by a medium-sized article, and then several short articles; with 5-6 notochaetae per bundle (body width 5 mm)............ T. havaica (Kinberg, 1867) n. comb.
13. Tunic smooth, transparent (at least in the anterior region); median chaetigers with about 10 notochaetae per bundle (body width 9 mm).......... T. minuta (Blanchard in Gay, 1849) n. comb.
— Tunic papillose, looking rugose or areolated, opaque or, if transparent, with fewer notochaetae.............................................................................................................. 14
14. Tunic grayish to reddish, finely speckled with tiny black spots; 5-8 notochaetae per bundle (body width up to 10 mm), each with short articles basally, medium-sized medially, longer distally.............................................................................................. T. salazarae n. sp.
— Tunic whitish (transparent in juveniles), without any dark spots; 4-5 notochaetae per bundle (body width 3 mm), each with long articles only............... T. jareckiorum n. sp.
15. Tunic with sediment grains on dorsal and ventral surfaces........................................ 16
— Tunic without sediment grains................................................................................. 25
16. Sediment grains large, completely covering the tunic................................................ 17
— Sediment grains variable, often small; if large, often embedded in the tunic, without concealing it............................................................................................................. 20
17. Sediment particles completely immersed in the tunic; first short neurohooks from chaetiger 5; anchylosed neurohooks bidentate, slightly expanded subdistally, from chaetiger 25....................................................... T. chilensis (Hartman, 1967) n. comb.
— Sediment particles partially immersed in the tunic................................................... 18
18. Anterior chaetigers with dorsal tubercles.................................................................. 19
— Anterior chaetigers without dorsal tubercles; anchylosed neurohooks from chaetigers 18-20; neurohooks with accessory tooth about as long as fang..... T. avicularia Caullery, 1944
19. Anchylosed neurohooks from chaetiger 14; neurohooks with accessory tooth longer than fang.............................................................. T. indica (Fauvel, 1928) n. comb., n. stat.
— Anchylosed neurohooks from chaetiger 40; neurohooks with accessory tooth about as long as fang.................................................................................... T. enigmatica n. sp.
20. Sediment particles often small, completely covering the tunic or dispersed throughout it.................................................................................................................................. 21
— Sediment particles larger, dispersed throughout the tunic......................................... 24
21. Anterior chaetigers with both notopodial and dorsal tubercles.................................. 22
— Anterior chaetigers with notopodial tubercles; dorsal tubercles absent............. T. eliasi n. sp.
22. Dorsal tubercles extending through a short anterior region, up to chaetiger 10 (body 5 mm wide); anchylosed neurohooks from chaetiger 32................... T. orensanzi n. sp.
— Dorsal tubercles extending through a larger anterior, over at least 20 chaetigers........ 23
23. Anchylosed neurohooks from chaetiger 25; dorsal tubercles extending up to chaetiger 25 (body 5 mm wide)............................................... T. hospita (Fauchald, 1972) n. comb.
— Anchylosed neurohooks from chaetiger 20; dorsal tubercles extending up to about chaetiger 40 (body 10 mm wide)........................................................ T. harrisae n. sp.
24. Anterior chaetigers with notopodial lobes, without dorsal tubercles; first short neurohooks from chaetiger 10; anchylosed neurohooks from chaetiger 40............... T. fauveli n. sp.
— Anterior chaetigers without notopodial or dorsal tubercles; first short neurohooks from chaetiger 5; anchylosed neurohooks from chaetiger 28..................... T. capitata (Nonato, 1966) n. comb.
25. Tunic smooth, papillae barely visible dorsally, median chaetigers almost without emerging papillae; anterior chaetigers with notopodial tubercles.............................................. 26
— Tunic papillose or velvety, not smooth...................................................................... 27
26. Chaetigers 2-5 with large notopodial lobes, larger in chaetigers 3-5; all neurohooks anchylosed from chaetiger 26; 6-7 notochaetae per bundle................. T. bastidai n. sp.
— Chaetigers 2-3 with large notopodial lobes, not visible in other anterior chaetigers; all anchylosed neurohooks from chaetiger 32; 7-8 notochaetae per bundle....................................................................................... T. borealis (Hartman, 1965) n. comb.
27. Median chaetigers with 6-9 transversal rows of papillae per segment; anchylosed neurochaetae slightly expanded medially, starting from chaetiger 50; tunic appearing smooth........................................................................................................................... T. fiegei n. sp.
— Median chaetigers with about 15 transversal rows of papillae per segment; anchylosed neurohooks markedly medially expanded, starting from chaetiger 45; tunic velvety or rugose.......................................... T. fernandensis (Augener, 1918) reinstated, n. comb.