▁of ▁War wick ▁( 2 0 0 7 ). ▁Many ▁more ▁references ▁at ▁the ▁web ▁page ▁of ▁American ▁Mathemat ical ▁Society ▁here . ▁ ▁Category : E lect oral ▁systems <0x0A> </s> ▁Cl an cul us ▁lim b atus , ▁common ▁name ▁the ▁ke e led ▁cl an cul us , ▁is ▁a ▁species ▁of ▁sea ▁sn ail , ▁a ▁marine ▁g ast rop od ▁m oll usk ▁in ▁the ▁family ▁Tro ch idae , ▁the ▁top ▁sn ails . ▁ ▁Description ▁The ▁size ▁of ▁the ▁shell ▁var ies ▁between ▁ 1 3   mm ▁and ▁ 2 0   mm . ▁The ▁de pressed , ▁um bil icate ▁shell ▁has ▁a ▁con oid al ▁shape . ▁It ▁is ▁car inate ▁at ▁its ▁peri ph ery . ▁Its ▁color ▁is ▁wh it ish ▁or ▁yellow ish , ▁mac ulated ▁with ▁brown , ▁generally ▁with ▁a ▁series ▁of ▁bl ot ches ▁at ▁the ▁peri ph ery ▁and ▁beneath ▁the ▁s uture , ▁the ▁interven ing ▁space ▁un icol ored ▁or ▁more ▁or ▁less ▁t ess ell ated . ▁The ▁base ▁of ▁the ▁shell ▁is ▁t ess ell ated ▁or ▁radi ately ▁fl amed . ▁The ▁sp ire ▁is ▁low ▁con ical ▁with ▁an ▁ac ute , ▁smooth ▁a pe x ▁. ▁The ▁ 5 ▁to ▁ 6 ▁wh or ls ▁are ▁convex ▁just ▁below ▁the ▁s ut ures , ▁then ▁fl atten ed , ▁and ▁at ▁the ▁peri ph ery ▁car in ated . ▁The ▁s ut ures ▁are ▁sub can al ic ulate