In a medium bowl, combine 1/3 cup lime juice, the orange juice, vinegar, 2 T of cilantro, jalapeno and half of the red onion. Cut the scallops in half crosswise. Stir the scallop halves into the marinade. Cover and refrigerate for 16-24 hours, stirring once or twice. Section the blood orange, orange and lime, remove membranes. Cut each section into 2-3 smaller pieces. Place the pieces in a small bowl. Add remaining 3 T of cilantro to the bowl. Set aside. When ready to assemble, peel the avocado, cut it into chunks, and place in the bowl of a food processor. Add the remaining 2 T of lime juice and puree until smooth, about 20 seconds. Season with salt & pepper to taste. Place the avocado puree in a resealable plastic bag. Strain the liquid from the ceviche. Cut each scallop into quarters. Set aside. Cut off a corner of the plastic bag. Pipe about 1t of avocado puree into each corn cup. Top with 2 pieces of the scallops and garnish with citrus and cilantro mixture. Serve right away. Makes about 3 ½ dozen.