Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 23

Published in Proceedings of the Academy of Natural Sciences of Philadelphia (Proc. Acad. Nat. Sci. Philad.), in 1907, in volume 59, pages 24-81

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 144

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 149

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 150

Published in Proceedings of the Academy of Natural Sciences of Philadelphia (Proc. Acad. Nat. Sci. Philad.), in 1907, in volume 59, pages 151-192

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 194

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 208-219

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 249-269

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 273-278

Published in Proceedings of the Academy of Natural Sciences of Philadelphia (Proc. Acad. Nat. Sci. Philad.), in 1907, in volume 59, pages 279-395

Published in Proceedings of the Academy of Natural Sciences, Philadelphia, in 1907, in volume 59, pages 370-395

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 418

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 445-446

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 447

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 448-451

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 452-460

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 461-466

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 514-559

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 564-565

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 567-569

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1907, in volume 59, pages 572-577

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1907, in volume 1907, pages 3-22