[ 49 J 



FURTHER REPORT ON PARASITES 



FOUND IN CONNECTION WITH THE 



PEARL OYSTER FISHERY AT CEYLON. 



BY 

 ARTHUR E. SHIPLEY, M.A., F.R.S., 



FELLOW AND TUTOR OF CHRIST'S COLLEGE, CAMBRIDGE, 



JAMES HORNELL, F.L.S., 



MARINE BIOLOGIST TO THE CEYLON GOVERNMENT AND INSPECTOR OF PEARI. BANKS. 



[With ONE PLATE.] 



The following short Paper is based on material collected by Mr. Hornell largely 

 from Elasmobranchs which frequent the Pearl Beds of Ceylon. The specimens 

 unfortunately arrived too late for our account of them to be incorporated in the 

 article on the " Parasites of the Pearl Oyster," published in the second volume of 

 this Report, but as some of the forms are new and the Cestodes may possibly, though 

 perhaps not probably, be the parent form of the pearl-producing larvae, it has seemed 

 advisable to publish this further instalment. Unfortunately our further researches 

 throw no direct light on the problem of the 'provenance of the pearl-producing 

 parasite. 



I. CESTODA. 



Staurobothrium setiobatidis, n. gen. et sp. Plate, figs. 1 and 2. 



A considerable number of tapeworms, with large cruciform heads, were taken from 

 the intestine of the Bird or Cockle-eating Ray, Mtiohatis uarinari, Marcg., at 

 Marichchukaddi, the centre of the recent pearl fishery. 



The head has the form of a cross with very short broad arms (Plate, fig. I). Each 

 arm ends in a sucker which, however, does not penetrate far into the arm, and whose 

 lumen is rather shallow. From the centre of the cross posteriorly arises the trunk, 



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