44 CEYLON PEARL OYSTER REPORT. 



I. CESTODA. 



We shall print the names of the fish-hosts In small capitals in the centre of the 

 line, the names of the Cestode parasites will be in Clarendon type, the genera in the 

 centre of the line, and the species at the left-hand margin. 



AETOBATIS NARINARI (Eufiirasen). 



The Tamil name is " Pua tirikkai." Occasionally it is also termed " Kuruvi 

 tirikkai," the "bird-ray"; but this latter is a somewhat general term applied to 

 several of the bird-like rays and analogous to our use of the term " eagle-ray." 

 Pua tirikkai is the true distinctive Tamil term. In Sinhalese it is " Pulli-maduwa." 

 Very characteristic features of this fish are the blue-black tint of the flesh, and the 

 manner in which the inner surface of the stomach is raised into a multitude of stout 

 fleshy papillae. 



The specimens dissected were : 



A. A small individual from Puttalam Lake, opposite Kalpitiya. Width of disc, 

 14|- inches; 6f inches between mouth and anus; length of tail, 32 inches. 

 December 30, 1904. 



B. A larger one from the open sea off Dutch Bay Spit. January 2, 1905. 



C. A third individual from same locality as B. January 6, 1905. Dimensions : 

 Width of disc, 27|- inches ; length of disc, 27 inches ; length of tail, 34 inches. From 

 the root of the tail to the root of the tail spine was 1 1 inches. 



Food: Specimen A. The stomach contents consisted entirely of the remains of 

 Lamellibranch shells and visceral masses. There were fully two hundred recognizable 

 pedal fragments, belonging apparently to a small Maclra and allied forms. 



B had been feeding principally upon the feet and siphons of Gastropods. A single 

 small Hermit-crab (Eupagurus sp.) was also present. The stomach of C was empty. 



Cephalobothrium, n. gen. 



A large, median, circular sucker takes up most of the head ; it is controlled by 

 longitudinal muscles. Four small spherical suckers are placed equidistant from each 

 other in the rim of the circular sucker. The proglottides are wider than broad, with 

 the exception of the last six or seven. The reproductive pores are lateral and very 

 irregularly alternate. 



Cephalobothrium aetobatidis. n. sp. Plate I., figs. 1, 2, 3 and 4. 

 This curious Cestode was drawn from life by Mr. Hornell in Ceylon, the enormous 

 terminal sucker being, in that state, much more conspicuous than in the preserved 



