Until the recent discovery of a sequence of properly embedded minimal surfaces with finite topology (Hoffman [4, 5]; Hoffman and Meeks [6, 7]), the only known examples were the plane, the catenoid and the helicoid. The existence of these new examples, which we will call Mk, k > 1, and others we have found (Callahan, Hoffman and Meeks [1]) makes it natural to ask qualitative questions about their behavior.It is a fundamental fact, due to Osserman [12], that if a complete minimal surface has finite total curvature, then it is, conformally, a closed Riemann surface punctured in a finite number of points; finite total curvature implies finite topology. The minimal surface Mk has total curvature equal to -47T(A; + 2). It is conformally a closed surface of genus k punctured in three points.A natural question to ask is whether or not each of the surfaces Mk lies in a one-parameter family of complete embedded minimal surfaces of finite total curvature. It is known that the plane and the catenoid are the unique embedded examples of finite total curvature with their respective topologies. In particular they cannot be perturbed through embedded examples. However In the case of genus k = 1, the surface Mi is conformally the square torus C/Z x Z, punctured in the three half-lattice points. It can be deformed through a family of embedded minimal surfaces which are, conformally, rectangular tori punctured in the three half-lattice points. In general, the surfaces Mk have two catenoid-type ends and one flat end. (By an end of a complete minimal surface of finite total curvature, we mean the image in R 3 of a neighborhood of a puncture point. An embedded end is a "catenoid-type end" if it converges at infinity to an end of the catenoid. It is called a "flat end" if it converges at infinity to a plane. For embedded ends on complete minimal surfaces of finite total curvature, these are the only possibilities.) They contain k + 1 straight lines which meet at a common point P and diverge into the flat end. The perturbations have three catenoid-type ends and contain no lines. The symmetry group of Mk is the dihedral group D(2k + 2), generated