Autolytus pseudosimplex Augener 1924

Autolytus pseudosimplex Augener, 1924 (Fig. 82A–C)

Autolytus (Proceraea) simplex Verrill, 1900: 630.

Autolytus pseudosimplex nom. n. Augener, 1924c: 44.

Material examined. Bermuda: holotype on slide YPM 24277/24288.

Description. Holotype complete in poor condition; length 5 mm for 58 chaetigers, width 0.25 mm. Preserved material without colour markings. Ciliation not possible to assess.

Prostomium not possible to evaluate. Four eyes, with lenses, in trapezoid arrangement, anterior pair larger. Eyes separated; eyes spots absent. Palps not possible to separate from prostomium. Nuchal epaulettes not possible to assess.

Anterior appendages and all dorsal cirri in poor condition, not possible to evaluate. Cirrophores not possible to assess.

Parapodial lobes not possible to evaluate. Anterior chaetigers with 2 aciculae, 1 in posterior. Chaetal fascicle with 6–8 compounds in anterior chaetigers, 4–6 in median and posterior. Compound chaetae with small distal tooth (Fig. 82B). Single thin bayonet chaetae (Fig. 82C), subdistally denticulated, beginning at chaetiger 40.

Pharynx sinuation not possible to assess. Trepan in chaetiger 5 with 16–20 equal teeth (Fig. 82A). Basal ring present; infradental spines present (Fig. 82A). Proventricle equal in length to 4–5 segments in chaetiger 11–14 with 30–32 rows of square shaped muscle cells. Two anal cirri equal to half body width.

Additional information from literature. Verrill describes the antennae as equal to c. 3–4 times prostomial length; dorsal tentacular cirri, first and second dorsal cirri to be twice as long; ventral tentacular cirri to be about equal to antennae; succeeding dorsal cirri are short, from 1/6 to 1/2 the body width. The pharynx is folded. Bases of parapodia are dark coloured, but it is not clear if this observation is done using direct or transmitting light; it may well be the parapodial glands as seen in light microscope.

Reproduction. Schizogamy according to Verrill. He describes a specimen with a developing stolon at the 40th segment, 21 segments long, full of eggs. This could not be confirmed in the type, but perhaps Verrill observed this in another specimen.

Habitat. Unknown.

Distribution. North West Atlantic. Bermuda. Only known from type locality.

Remarks. Autolytus pseudosimplex is only known from this single individual in very poor state, and with present material it is not feasible to determine its status. It may be synonymous with other Myrianida taxa with c. 16–20 equal teeth in its trepan, including M. australiensis, M. brevipes, M. edwarsi, M. quindecimdentata, and M. spinoculata. Autolytus pseudosimplex is currently insufficiently known, and is here referred to as Myrianida incertae sedis.