A new borosilicate molecular sieve, CIT-1, is synthesized using N,N,N-trimethyl-(-)-cis-myrtanylammonium (I) hydroxide as the organic structure-directing agent. The material is characterized by synchroton X-ray powder diffraction (XRD), electron diffraction, solid-state NMR and IR spectroscopies, scanning electron microscopy, and physical adsorption experiments. Rietveld refinement of the synchrotron XRD data (Rp = 9.9%, Rwp = 11.9%) shows that CIT-1 is essentially the pure polymorph B of the molecular sieve SSZ-33 (space group C2/m, no. 12, a = 22.6242(10) Angstrom, b = 13.3503(4) Angstrom, c = 12.3642(6) Angstrom, and beta = 68.913(4)degrees). CIT-1 is the first synthetic molecular sieve to contain interesting 10- and 12-ring pores that is not an intergrowth of two different polymorphys. The long-range ordering of CIT-1 is shown to be a direct consequence of the organic structure-directing agent. CIT-1 can be easily prepared and sequential treatments of the calcined form of the calcined form of CIT-1 with aqueous HCl, and aqueous aluminum nitrate remove framework boron and insert aluminum into the structure, respectively. Aluminum-containing CIT-1 is a very active catalyst for the cracking of n-butane at 783 K.