71 CEYLON PEARL OYSTER REPORT. 



succeeding proglottis. Only at the hinder end are the proglottides as long as they 

 are broad, and only the last three or four are longer than they are broad. The 

 incurved tail seemed characteristic, at any rate it occurred in both our specimens. 



The body was too thick and too opaque for us to make out any details of the 

 internal anatomy. 



The diagnosis of Rhinebothrmm ceylonicum is as follows : 



Head with sessile or almost sessile bothridia, each with two rows of some twenty 

 transverse areolas. Body very stout, 3 millims. in its widest part ; very thick, 

 2 millims. ; and varying from 3 centims. to about 5 "8 centims. in length. Proglottides 

 with salient posterior edges, mostly much broader than long, but the last few longer 

 than broad and a few squarish. Tail incurved. 



Habitat : Trygon kuhli, spiral intestine. According to the collector, the same 

 species occurs both in Mylidbatis maculata and in Trygon walga. 



In the same bottle with these two worms was another of a different kind, but 

 whose head was so damaged that it is impossible to accurately diagnose it. 



Tylocephalum kuhli, n. sp. Plate V., figs. 76 and 77. 



A single specimen was taken from the intestine of Trygon kuhli. It measured 

 12 millims. in length, and its greatest width, which lies a little before the posterior 

 end, is 0'6 millim. The head consists of two portions, something like a cottage loaf, 

 and in general resembling those of T. uarnak and T. trygonis. The anterior part or 

 myzorhynchus is, however, somewhat smaller than in those species. The larger and 

 posterior part bears four small spherical suckers. The muscles which enter the head 

 from the body spread out in this portion in a button-like manner. Immediately 

 behind the head is a constriction, and then the j^roglottides begin. 



At first the proglottides are very shallow, with projecting rims like a pile of saucers 

 upside down, then about half-way along the body each proglottis is seen to have a 

 groove in it dividing it into approximately equal halves. If we trace the proglottides 

 still further back, we see that these two halves have very different fates ; the anterior 

 becomes the proglottis full of reproductive organs, etc. (Plate V., fig. 76), the 

 posterior becomes the pronounced, everted, and almost recurved, salient edge. 



The hindermost proglottis is square, and in no case is the longitudinal diameter 

 greater than the transverse. The last two or three proglottides had the penis 

 protruded, and these were all on the same side. 



The diagnosis of Tylocephalum kuhli is as follows : 



This form measured 12 millims. in length by - 6 millim. in width at the widest 

 point. Head separated from body by a sharp constriction. Proglottides at first very 

 shallow, and never longer than broad. About the middle of the body each proglottis 

 is divided into two halves, the posterior does not develop so quickly as the anterior 

 and forms the very marked, recurved, salient, posterior angle. 



Habitat : Intestine of Trygon kuhli. 



