Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 266

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 208-209

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 122-123

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 136-158

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 267

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 455

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 482-485

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 479-481

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 124-135

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 209

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 506-507

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 71-72

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 406-407

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 409

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 210-223

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 342-388

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 411-430

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 439

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 76-93

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 499-500

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 508-509

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 73-74

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 165-171

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 160

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 224-233

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 496-497

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 234-236

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 485-487

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 118-120

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 120

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 458-463

Published in Proceedings of The Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 56-61

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 400-405

Published in Proceedings of the Academy of Natural Sciences of Philadelphia, in 1891, in volume 43, pages 389-398