Phormosoma bursarium A. Agassiz 1881

Fig. 22 A–C.

Phormosoma bursarium: A. Agassiz, 1881: 99 . Pl. X, Fig. b; Alcock & Anderson, 1984: 192; H.L. Clark, 1924: 3; H.L. Clark, 1925a: 54; Mortensen, 1935: 135 –141. Pl. II, Fig. 20. Pl. III, Figs 1–2. Pl. LXXIV, Figs 11–15; A.M. Clark, 1977: 136; Clark & Courtman-Stock, 1976: 221; Schultz, 2011: 1071, Figs 1865–1868.

Material examined. A22124; A22219; A22248; A22251.

Identification. Oral side slightly arced, aboral side distinctively low-hemispherical. Tubercles and associated areoles particularly large and conspicuous. Primary spines coarse, upper ones being more or less distinctively curved.

Global maximum size. Maximum test diameter 128 mm.

Global distribution. East coast region of South Africa and Arabian Sea to Japan, Hawaii and New Zealand; at 170 – 2340 m depth (Mortensen 1935; Schultz 2011).

Remarks. Species shows variation in many characters, such as number of tubercles orally and aborally and arrangements of tubercles, which may be limited to distal parts, or extend to apex.