16 PROCEEDINGS OF THE NATIONAL MUSEUM. 



EXPLANATION OF PLATES. 



ci, cirrus. 



cp, cirrus-pouch. 



ed, dorsal excretory vessel. 



ev, ventral excretory vessel. 



ga, genital aperture. 



gd, germ duct. 



Im, longitudinal muscle. 



n, nerve. 



0, ovary (gerraarium). 



sd, sperm duct. 

 sg, shell gland. 

 t, testes. 

 «, uterus. 

 V, vagina. 

 vd, vas deferens. 

 vg, vitelline gland. 

 yd, vitelline duct. 



Figures 1,2,4,5,7,8,11,12, Phyllohothrium tumidiim new species, from Car- 

 charodon carcharias; figures 3, 6, 10, and 13 of the same, from I sums dekayi. 



Plate 1. 



Fig. 1. Scolex ; dorso-ventral view ; drawn from an alcoholic specimen. Actual 

 diameter 2.1 mm. 



2. Front view of scolex mounted in balsam ; partly diagrammatic, folds, 



which partly covered the auxiliary suckers, having been omitted ; 

 greatest diameter 4.6 mm. 



3. Single bothrium of scolex fixed while attached to mucous membrane of 



host, mounted in balsam ; diameter of auxiliary sucker 0.35 mm. 



4. Proglottides, 15 mm. from scolex ; balsam ; breadth 1.5 mm. 



5. Posterior ends of three strobiles; balsam; length of longest 9 mm. 



6. Transverse section of mature, but unripe, proglottis, a little in front 



of the genital aperture ; greatest diameter 1 mm. 



Plate 2. 



Fig. 7. Free proglottis, mature but unripe; balsam; length 5 mm. Sketch by 

 George T. Kline. 



8. Free, ripe proglottis ; balsam ; length 7.5 mm. 



9. Diagram showing relation of ducts of reproductive organs in vicinity of 



the shell gland of Phyllohothrium tumiduni new species., 

 10. Detail of longitudinal muscles in cross section, figure 6. 



Plate 3. 



Fig. 11. Sagittal section, somewhat slanting, of anterior end of scolex, showing 

 ganglion cells and exretory vessels ; diameter of auxiliary sucker 0.25 

 mm. 

 12. Ganglion cells in sections of scolex. o, cells in parenchyma ; h, black 

 of bothrium, and cells associated with muscle fibers; c, wall of auxil- 

 iary sucker; d, cells and muscle fibers at base of pedicel; e, mar- 

 ginal region of bothrium ; /, central region of bothrium ; camera lucida 

 drawings with Spencer No. 6 ocular, and 0.4 mm. objective. 



13. Sagittal section of cuticle ; see text. 



14. Larval Phyllobothrium from swordfish ; balsam ; length l.,54 mm. 



15. Larval Phyllobothrium from swordfish ; much flattened at time of fix- 



ing ; balsam ; breadth of neck at base of scolex 0.75 mm. 



