Genus Myrsidea Waterston

Myrsidea Waterston 1915: 12. Type species: Myrsidea victrix Waterston by original designation.

Because a thorough characterization of this genus is available in Clay (1966), we will provide here only the features that are significant in defining the genus as it pertains to cotinga lice.

Head (Fig. 1) anteriorly rounded; without lateral notch or slit; inner occipital setae long, outer minute; without ventral sclerotized processes; each side of gula with heavier longer posterior seta; hypopharyngeal sclerites well developed.

Thorax (Figs. 1, 5) with pronotum having 6 posterior setae; without central setae; with 3 short setae at each lateral angle. Mesonotum with 2 minute medioanterior setae adjacent to postnotum and 2 at posterior margin. Metanotum without central setae. Prosternal plate well developed, elongate, with 2 short anterior setae; metasternal plate large, diamond shaped, usually with 6 setae, much less often 5 or 7; venter of femur III with setal brush. Abdomen (Figs. 1, 4–6) with undivided tergites, without anterior setae except for very small corner seta on each side of tergite I; sternite I small, without setae; sternite II enlarged, with aster of 4 heavy setae at each lateroposterior corner. Pleurites without anterior setae. Female anus oval, without inner setae; subgenital plate of fused sternites VII– IX, with lightly serrated posterior margin. Male subgenital plate of fused sternites VIII– IX; genitalia of characteristic shape (Fig. 2), with spinous sac having associated sclerites (Fig. 3). Sexual dimorphism limited to male with smaller dimensions, sparser abdominal chaetotaxy, and differences associated with genitalic features of posterior abdomen. Female with either gross enlargement of anterior abdominal tergites (Fig. 4) or with essentially unmodified tergites (Fig. 6). Male tergal segments unmodified (Figs. 1, 5). For brevity, we will not repeat these generic characters in discussing each species.