Atopsyche

Key to males of Atopsyche species from Brazil

1 First article of each inferior appendage without apicomesal projection (subgenus Atopsyche)........................ 2

- First article of each inferior appendage with apicomesal projection (subgenus Atopsaura (A.) longipennis Group)........ 5

2(1) Second article of each inferior appendage tapered from base and hooked ventrad (A. bolivari Group)................... 3

- Second article of each inferior appendage broadened at base and trianguloid (A. tripunctata Group)................... 4

3(2) Posterolateral beaks of phallotheca posteriorly each divided into two long, paired processes, dorsal process longer and bifur- cate apically, ventral process curved mesad and crossing process from opposing beak (Santos & Holzenthal 2012, fig. 2D).............................................................................................. A. parauna

- Posterolateral beaks of phallotheca posteriorly wide, truncate or shallowly divided, with apicoventral corners downturned (Santos & Holzenthal 2012, fig. 2E–G)........................................................... A. urumarca

4(2) Second article of each inferior appendage evenly tapering and rounded at apex (Ross & King 1952, fig. 3A)...... A. erigia

- Second article of each inferior appendage obtuse and truncate at apex (Schmid 1989, pl. XVI, fig. 1)........ A. chirihuana

5(1) Filipods absent (Fig. 1 A)............................................................................... 6

- Filipods present (Fig. 2 A)............................................................................ 14

6(5) Phallotheca without dorsal process (Fig. 3 E)................................................................ 7

- Phallotheca with dorsal process (Fig. 1 B)................................................................ 12

7(6) Apical portion of first article of each inferior appendage bifurcate (Fig. 4 C)...................................... 8

- Apical portion of first article of each inferior appendage not bifurcate (Schmid 1989, pl. XVII, fig. 5)................. 10

8(7) Basodorsal process of phallotheca elongate, curved, spine-like (Fig. 4 E)....................... A. kamakan new species

- Basodorsal process of phallotheca broadening at tip (Flint 1974, fig. 27)......................................... 9

9(8) Beaks of phallotheca each with lateral thin, deeply bifurcate lobe at mid-length (Flint 1974, fig. 27)......... A. sanctipauli

- Beaks of phallotheca without lateral thin, deeply bifurcate lobes (Schmid 1989, pl. XVII, fig. 9)................ A. huarcu

10(7) Basodorsal process of phallotheca longer than inferior appendages (Schmid 1989, pl. XVII, fig. 5)......... A. huamachucu

- Basodorsal process of phallotheca shorter than inferior appendages (Schmid 1989, pl. XVII, fig. 3)................... 11

11(10) Basodorsal process of phallotheca tapering at tip (Schmid 1989, pl. XVII, fig. 3)........................ A. huacachaca

- Dorsal process of phallotheca broadening at tip (Schmid 1989, pl. XVII, fig. 8).......................... A. hatunpuna

12(6) Inferior appendages each with apicoventral process (Marlier 1964, fig. 3A)............................... A. plancki

- Inferior appendages without apicoventral processes (Figs. 3 C, 3G)............................................ 13

13(12) Parapods forked and terminating in two slender branches (Schmid 1989, pl. XVIII, fig. 10)................. A. apurimac

- Parapods not forked, but apicodorsally with upcurved sclerotized projection (Fig. 3 C).......... A. diamantina new species

14(5) Filipods shorter than parapods (Fig. 2 A)................................................................. 15

- Filipods longer or about as long as parapods (Santos & Holzenthal 2012, fig. 1A)................................ 19

15(14) Inferior appendages downcurved at midlength (Ross 1953, fig. 9A)........................................... 16

- Inferior appendages straight (Schmid 1989, pl. XVII, fig. 6)................................................... 18

16(15) Short thumb-like process present mesoventral of filipods and parapods and above phallotheca (Ross 1953, fig. 9A) … A. serica

- Thumblike process absent (Fig. 5 C)...................................................................... 17

17(16) Phallic apparatus with middorsal hood (Flint 1971, fig. 2)................................................ A. siolii

- Phallic apparatus without middorsal hood (Fig. 5 D)....................................... A. muelleri new species

18(15) Second article of each inferior appendage pyriform; parapods about as long as basal height, abruptly taller in apical third (Schmid 1989, pl. XVIII, fig. 2)................................................................ A. acahuana

- Second article of each inferior appendage only slightly larger basally, not pyriform; parapods four times longer than tall, each with dorsal margin forming slight discontinuity in apical third (Schmid 1989, pl. XVIII, fig. 6)............... A. antisuya

19(14) Filipods about as long as parapods (Ross & King 1952, fig. 21A)............................................. 20

- Filipods longer than parapods (Santos & Holzenthal 2012, fig. 1A)............................................ 21

20(19) Beaks of phallotheca each bearing short, strongly sclerotized posteroventral spine beneath long, setose, upturned process (Ross & King 1952, fig. 21B)......................................................................... A. hamata

- Thumb-like process absent mesoventral of filipods and parapods (Ross & King 1952, fig. 22A)............. A. longipennis

21(19) Phallotheca with long paired processes (Santos & Holzenthal 2012, fig. 1E)..................................... 22

- Phallotheca without long paired processes (Schmid 1989, pl. XVII, fig.14)...................................... 23

22(21) Beaks of phallotheca with several spines on their lateral edges; filipods exceeding length of parapods (Santos & Holzenthal 2012, fig. 1A, 1B)............................................................................. A. blahniki

- Beaks of phallotheca without spines on their lateral edges (Fig. 2 B; Flint 1974, fig. 24)........................ A. zernyi

23(21) Second article of each inferior appendage dactylate (Denning & Sykora 1968, fig. A)....................... A. usingeri

- Second article of each inferior appendage concave on mesal face (Schmid 1989, pl. XVII fig. 14)............ A. huanapu