Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 4

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 71-82

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 83

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 121-124

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 145-177

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 178

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 179-182

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 185-187

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 195-200

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 201-216

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 219-224

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 225

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Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 228-244

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 254-257

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 258

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 276-280

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 324-364

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 377-378

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 379

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 403-405

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 407-432

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 465

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 478

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 480-481

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 482-496

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 498-500

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 524

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 538-540

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 541-542

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 548-550

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Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1899, in volume 51, pages 551

Published in Proceedings of the Academy of Natural Sciences, in 1899, in volume 51, issue 1, pages 5-62

Published in Proc. Acad. Nat. Sci. Philadelphia, in 1899, in volume 1899, pages 183-184

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1899, in volume 1899, pages 259-275