896 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [178] 



PLATE XV. 



Tetrarhynchu8 bisulcatum Lt. 



Fig. 1. Portion of pyloric division of the stomach of Carcharias obscurus with the para- 

 sites attached to the mucous membrane. In some cases two or more 

 scolices are buried in a common pit, X 1£. 



Syndesmobothrium filicolle, sp. nov. 



Fig. 2. Sketch of alcoholic specimen, X 15. The specimen is immature and the pos- 

 terior part a is evidently a blastocyst from which the anterior part or 

 scolex has been everted. 



Fig. 3. Hooks, the smaller ones from the base, the larger from the middle of a pro- 

 boscis, X 200. 



Fig. 4. View of top of head, from alcoholic specimen, X 50. 



Paratcenia medusia, gen. et sp. nov. 



Fig. 5. Strobile; outline from living specimen; details of anatomy supplied from alco- 

 holic specimen, x 15. The last two segments are filled with ova. The 

 tentacular proboscides were everted after the specimen had been placed 

 in alcohol. 



Fig. 6. Outline of strobile, from alcoholic specimen, the tentacular proboscides re- 

 tracted, X 18 ; a, terminal os into w r hich the proboscides are retracted. 



Fig. 7. Outline of strobile with three of the tentacular proboscides protruding, from 

 alcoholic specimen, X 18. 



Fig. 8. Top of head, all the tentacular proboscides extended, making a terminal 

 rosette, or sixteen-rayed crown, from alcoholic specimen, X 200. 



Fig. 9. Side view of head showing tentacular proboscides and two of the bothria, 

 from alcoholic specimen, X 200. 

 Figures 6, 7, 8, and 9, by the author, the others by Margaret B. Linton. 



