Node.js error crawling with npm crawler

When using the npm crawler to crawl links, I get the error:

C:\Users\ryani\Desktop\JavaScript\crawler\crawler.js:15
                                $('a').each(function(index, value) {
                                      ^

TypeError: Cannot read property 'each' of undefined

I've tried setting timeouts and various debugging techniques... I'm not sure why it is getting undefined; when I put the code in a tag on an html page, it works fine.

crawler.js:

var Crawler = require("crawler");

var c = new Crawler({
    "maxConnections":10,

    "callback":function(error, res, $) {

        if (error) {
            console.log("error");
            console.log(error);
        } else {
            $('a').each(function(index, value) {
                console.log($(this).attr('href'));
                //c.queue(href)
            });
        }
    }
});

c.queue('http://www.google.com');

via Ryan Walker