Helminth Fauna of the Dry Tortugas. 189 



49. Base of proboscis; diameter of enlargement, exclusive of hooks, 0.07 mm. 



50. Another view of base of proboscis; diameter of enlargement, exclusive of hooks, 



0.07 mm. 



51. Another view of proboscis; diameter, exclusive of hooks, 0.031 mm. 



52. Types of hooks; length 0.020 to 0.028 mm. 



53. Segments near posterior end of strobile; maximum diameter 0.35 mm. 



54. Free segment, partly diagrammatic. Testes represented a little larger than natural; 



vitelline glands partly cover testes in nature; length 5.5 mm. 



PLATE 8. 

 Rhynchobothrium binuncum sp. nov., from Dasyatis say. 



55. Strobile, balsam ; actual length 5 mm. 



56. Head, neck, and anterior end of the body, balsam; length of head and neck 



1.25 mm. 



57. 58. Different views of base of proboscis, showing characteristic paired hooks; 



length of largest hooks 0.03 mm. 



59. Another view of proboscis; diameter, exclusive of hooks, 0.03 mm. 



60. View of proboscis towards distal end; diameter, exclusive of hooks, 0.035 mm - 



61. 62, 63. Different views of paired hooks which are situated near the base of each 



proboscis. The pairs shown in these sketches are from different proboscides ; 

 length of longest 0.030, 0.031, and 0.035 mm. in the several pairs. 



64. Posterior segment, specimen mounted in balsam ; actual length 2.41 mm. Length of 



strobile from which this sketch was made 5.97 mm. 



PLATE 9. 



Rhynchobotliriiun sp., from Ginglimostoma cirratum. 



65. Entire specimen, showing head, neck, and rudimentary strobile, balsam; actual 



length 3.5 mm. 



66. View of proboscis near base; diameter, exclusive of hooks, 0.056 mm. The hooks 



become yet denser a little anterior to the point shown in the sketch. 



67. View of proboscis near distal end, opposite to view shown in fig. 68; diameter 



of proboscis, exclusive of hooks, 0.045 mm. 



68. View opposite to that shown in fig. 67. 



69. Posterior end of strobile, much enlarged, showing terminal pore of the excretory 



system; length of segment 0.26 mm. 



PLATE 10. 

 Rhynchobothrium sp., from Ginglimostoma cirratum. 



70. Head and neck, balsam; actual length 2.10 mm. 



71. View of proboscis near base; diameter, exclusive of hooks, 0.06 mm. 



72. View of proboscis 0.5 mm. from base (as much as was exserted) ; diameter, ex- 



clusive of hooks, 0.05 mm. 



73. View of proboscis opposite to that shown in fig. 72. 



74. Next to last segment, balsam; actual length 2.24 mm. 



Rhynchobothrium sp., from Lycodontis funebris. (Encysted stage of preceding species.) 



75. View of proboscis on opposite side from that shown in fig. 76, and a little in front 



of it ; diameter, exclusive of hooks, 0.038 mm. 



PLATE n. 



Rhynchobothrium sp., from Lycodontis funebris, continued. 



76. View of proboscis opposite to that shown in fig. 75, near base ; diameter, exclusive 



of hooks, 0.040 mm. 



77. Blastocyst with larva, sketch from life; actual length 4.34 mm. /, larva. 



