Valettaster argus (Spencer, 1907)

(Figs 6H–K, N, O, 7P, R, 8K, M, 22L, 23B–P)

1850 fragment of an Oreaster Forbes in Dixon: pl. 21, fig. 16.

$1907 Stauranderaster argus Spencer: 99, pl. 29, fig. 8.

1913 Tholaster argus (Spencer); Spencer: 138, pl 13, fig. 25.

1914 Valettaster ocellatus (Forbes); Valette: 60, fig. 20.

1985 Valettaster argus (Spencer); Breton: 91, fig. 6.

Type. An individual (not figured) from the Marsupites Zone of Brighton, southern England (NHMUK E 5109) is the holotype .

Diagnosis. Valettaster in which the abactinal ossicles possess small external faces and bear a reticulate sculpture.

Material. A well-preserved specimen from the coranguinum Zone of Micheldever, Hampshire (NHMUK E 20294) and a partly articulated specimen from the same zone at Thanet, Kent, provide many details of the ossicles and nature of the abactinal surface (NHMUK EE 17637).

Occurrence. Valettaster argus is present in the Turonian to Campanian Chalk of the United Kingdom.

Remarks. The new material provides information on the nature of the exterior surface of this species (Fig. 23H–K). The spaces between the large abactinal ossicles are packed with smaller, secondary ossicles of various sizes (Fig. 23H), creating a smooth surface made up of the exposed summits of the larger ossicles and the smaller plates (Fig. 23 I, J). There are spaces between the smaller ossicles, which might represent papular pores (Fig. 23J), or where secondary ossicles have fallen out. It is important to point out that the reconstruction of Breton (1985, fig. 4), which shows the surface of the asteroid with a thick dermis, containing numerous small ossicles, is incorrect.