McCormick & Schmick's ( MSSR) was among the biggest small-cap losers Tuesday in a mostly down day for the sector. Shares plunged 23.1% after the Portland, Ore., seafood-restaurant chain sliced 5 cents off the low end of its prior third-quarter income guidance to about 16 cents a share. Same-store sales are now pegged to be flat vs. the prior forecast for a gain of between 1.5% and 2.5%, and the total-sales estimate was lowered by $2 million from the earlier low end to roughly $88 million. Thomson Financial's estimates call for 22 cents a share, less extraordinary items, on total revenue of $90.6 million. McCormick shares lost $5.78 to $19.28. Another small-cap name, Panacos Pharmaceuticals ( PANC), slid 21% on news chief financial officer Peyton Marshall had resigned. VP Robert Pelletier will replace him in the interim. Shares of the Watertown, Mass., biotech company were off 53 cents at $1.99. And Standard Pacific ( SPF) sank 10.6% after UBS began coverage on the Irvine, Calif., homebuilder with a sell rating. The move comes a day after the company priced a $100 million convertible-senior-bond offering and eliminated its 4-cent quarterly dividend. Standard Pacific shares shed 75 cents to $6.30. That helped pressure the Russell 2000, which also harbors McCormick, as well as the S&P SmallCap 600. Both trackers were lately losing around 0.4%.