mongoose recursive schema definition that includes model (fails)

A.js

define([
  'mongoose'
, './Cm'
], function(
  mongoose,
  Cm
) {

  var A = new mongoose.Schema({
    name: String
  });

  return A;
});

B.js

define([
  'mongoose'
, './A'
], function(
  mongoose,
  A
) {

  var B = new mongoose.Schema({
    name: String
  });

  return B;
});vi 

C.js

define([
  'mongoose'
, './B'
], function(
  mongoose,
  B
) {

  var C = new mongoose.Schema({
    name: String
  , ref: [B]
  });

  return C;
});

Cm.js

define([
  'mongoose'
, './C'
], function(
  mongoose,
  C
) {
  return mongoose.model('Cm', C);
});

run.js

var requirejs = require('requirejs')
, mongoose = require('mongoose');

requirejs.config({
  baseUrl: __dirname
, nodeRequire: require
});

requirejs([
  './A'
, './Cm'
], function(
  A
, Cm
) {

  var Am = mongoose.model('A', A);
  var a = new Am();
  var c = new Cm();

});

running this in node generates the following error:

  throw new Error('Schema hasn\'t been registered for model "' + name + '"
           ^
Error: Schema hasn't been registered for model "Cm".
Use mongoose.model(name, schema)
    at Mongoose.model (/home/donnut/dev/js/node_modules/mongoose/lib/index.js:222:13)
    ....