San Francisco-based Fundbox, a cash flow optimization tool for small businesses, has received $40 million in Series B funding. General Catalyst Partners led the round with participation from other investors that included Khosla Ventures, Shlomo Kramer, Blumberg Capital and NyCa Investment Partners. Also, Hemant Taneja of General Catalyst has been added to Fundbox’s board of directors. In addition to the Series B financing, Fundbox has also received a new credit facility from Silicon Valley Bank and other unidentified institutions. No financial terms were disclosed.