Published in Proceedings of the Academy of Natural Sciences, Philadelphia, in 1918, in volume 69, pages 309-333

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 2-71

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 72

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 73-74

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 81-85

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 114

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 120-126

Published in Proceedings of the Academy of Natural Sciences, Philadelphia, in 1918, in volume 70, pages 144-236

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 239-280

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 282-333

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 335-340

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 356-359

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 359

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1918, in volume 70, pages 360