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Rhyncholampas smithi Srivastava , Singh, Tiwari & Jauhri, 2008, p. 514

Diagnostic Features	Test medium, subcircular to oval, truncated posteriorly; oral surface flat; highest point of the test at the apical system; margin tumid and well rounded. Apical system monobasal, circular, excentric anteriorly, ocular plates triangular in shape. Petals moderately long, subpetaloid to petaloid and do not reach the ambitus; III subpetaloid and short; paired petals petaloid, I & V longest and narrowest; poriferous zones of Ia, IIb, IVa and Vb are shorter than their fellows. Pore pairs are conjugated by slightly curved grooves. Peristome pentagonal, excentric anteriorly. Bourrelets and phyllodes (nucleolitid type) fairly well developed. Periproct transversely oval, supramarginal, close to the posterior ambitus on posterior truncation. Tubercles abundant, non-perforate and crenulate. Naked zone in Interambulacrum 5.
Distribution	Eocene (late Lutetian to early Bartonian); Meghalaya, India
Type	Holotype: Lucknow University Geology Department LUGD/I/2023; paratypes LUGD/I/2024 to LUGD/I/2026. Centre of Advanced Study in Geology, University of Lucknow, Lucknow.
Classification and/or Status	Cassiduloida; Cassidulidae A species of Rhyncholampas A. Agassiz, 1869
Remarks	Rhyncholampas smithi differs from R. grignonensis (Defrance) described from the Eocene sediments of France (Kier, 1962) in lacking flat aboral surface and straight petal III. It differs from R. caroliensis (Twitchel) described from the middle Eocene sediments of North Carolina (Kier, 1980) in having higher test and less developed phyllodes. It can be distinguished with living R. pacificus (A. Agassiz) of American west Coast (tropical eastern Pacific Ocean) in having more convex aboral surface, less developed phyllodes and subpetaloid petal III. Kier, P. M. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections, 143(3): 1-262, 44 pls. Kier, P. M. 1980. The echinoids of the middle Eocene Warley Hill Formation, Santee Limestone and Castle Hayne Limestone of North and South Carolina. Smithsonian Contributions to Paleobiology, 39: 102 p., 22 pls. Srivastava, D. K., Singh, A. P., Tiwari, R. P. & Jauhri, A. K. 2008. Cassiduloids (Echinoidea) from the Siju Formation (late Lutetian-early Bartonian) of the South Garo Hills, Meghalaya, India, Revue de Paleobiologie, 27(2): 511-523.