Pseudopotamilla

Knight-Jones, Phyllis, Darbyshire, Teresa, Petersen, Mary E. & Tovar-Hernández, María Ana, 2017, What is Pseudopotamilla reniformis (Sabellidae)? Comparisons of populations from Britain, Iceland and Canada with comments on Eudistylia and Schizobranchia, Zootaxa 4254 (2), pp. 201-220 : 214

Key to Pseudopotamilla species described here

1. Collar with high, well-developed, rounded lappets dorsally ( Fig. 1 D); dorsal margins V-shaped ( Figs 1 D, 2A); and peristomium well exposed dorsally ( Fig. 1 D, 1A) and laterally above collar margins ( Fig. 2 C)...... P. reniformis ( Bruguiére, 1789)

- Collar with low, rounded lappets dorsally ( Figs 4 C, 5C); dorsal collar margin convex ( Figs 4 C, 5C); and peristomium slightly exposed laterally ( Fig. 4 B) or not exposed above collar margins ( Fig. 5 B–C)..................................... 2

2. Lateral margins of collar V-shaped ( Fig. 4 B); handle of each companion chaeta twice length of handle of adjacent uncinus ( Fig. 4 K)........................................................................ P. aspersa ( Krøyer, 1856)

- Lateral margins of collar even (in line with the horizontal body axis) ( Fig. 5 B); handle of companion chaeta slightly longer than handle of adjacent uncinus ( Fig. 5 H)......................................... P. saxicava ( Quatrefages, 1866) .

Figures

FIGURE 1. Pseudopotamilla reniformis (Bruguiére, 1789), Neotype (NMW. Z. 2001.042.0001). A) Whole worm; B) radiolar compound eye; C) cross section of radiole; D) dorsal view of anterior thorax and crown base; E) same, ventral view; F) dorsal lip and dorsal radiolar appendage; G – H, J) collar chaetae; K) superior thoracic chaeta; L) inferior thoracic chaeta; M) abdominal chaeta; N) thoracic uncinus (right) and companion chaeta (left); P) different view of companion chaeta; Q) abdominal uncinus; R) tube showing distal enrolling and the branch of an offspring. Not scaled: B – C, Q & R.

FIGURE 2. Pseudopotamilla reniformis (Bruguiére, 1789), Neotype (NMW. Z. 2001.042.0001). Anterior of neotype in A) dorsal view; B) ventral view; C) lateral view.

FIGURE 4. Pseudopotamilla aspersa (Krøyer, 1856). A – J & P, N: Type ZMUC POL- 00523; K, L, M: lost Syntype, after Krøyer: A) ‘ whole’ worm, left crown missing, posterior damaged; B) antero-lateral detail of A; C) anterior thorax, dorsal view; D) same, ventral view; E) superior thoracic chaeta; F) inferior thoracic chaeta, front view; G) same, side view; H) side views of thoracic uncinus (left) and companion chaeta (right); J) view of companion chaeta showing teardrop-shaped ‘ blade’; K) uncinus and companion chaeta (after Krøyer); L) same, but part of torus; M) left side of crown; N) and P) two views of abdominal chaetae. Not scaled: H, J. Krøyer gave no scales for K – M.

FIGURE 5. Pseudopotamilla saxicava (Quatrefages, 1866) (NMW. Z. 2009.038.0903). A) Whole worm; B) thorax and crown, lateral view; C) same, dorsal view; D) same, ventral view; E) dorsal lip; F) superior thoracic chaeta; G) inferior thoracic chaeta; H) thoracic uncinus (right) and companion chaeta (left); J) abdominal uncini, three-quarter view. Not scaled: H, K.