Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1922, in volume 73, pages 437-448

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1922, in volume 74, pages 1-27

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1922, in volume 74, pages 29-67

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1922, in volume 74, pages 121-299