Length . . . . 50 mm. 



Breadth of last segment . . 1 mm. 



Length of last segment . . "4 nvna. 



CESTODE PARASITES. 273 



recurved. Head and neck covered with lines arranged in a criss-cross fashion. Short unsegmented 

 portion between proboscis sacs and first proglottid. Fii'st segments crowded, much broader than long. 

 They elongate gradually. Last one-third or one-fourth of the worm thick, and pigmented brown in 

 preserved specimens. Last segment 2-5 mm. long, 2 mm. broad, and '6 mm. thick. Gienital apertures 

 lateral and irregularly alternate. 



Habitat. — The spiral valve of Trygon kuhli. Fourteen specimens. November 27, 1910. 



Pa/ratcenia elongatus, n. sp. II. (Plate III., Fig. 40.) 

 The head is exactly similar to that of the only other species of this genus, viz., Paraloenia medusia, 

 Linton. 



The head is globular. There are fom' small bothridia. From the terminal os at the anterior 

 extremity about sixteen mobile tentacles may be protruded. Our species has a short neck, equal in 

 length to the head. First segments shallow, and all the segments broader than long, the anterior. ones 

 being slightly salient. The worm is whip-like and very narrow untU the ripe segments are reached. 

 The foUo wing are the measurements of our longest specimen : — 



Length of head . . • .5 mm. 



Breadth of head . . "4 mm. 



Length of neck . . '5 mm. 



The riper segments broaden suddenly. 



vSome specimens were strongly contracted, and these measured 39 mm. Our species thus differ 

 from Paralcenia medusia, Linton, in being ten times longer, in possessing a neck, and in the ripe segments 

 being broader than long. 



The diagnosis of Paratnnia elongattis is as foUows : — 



Head globular or subglobular, with four small bothi-idia. From the terminal aperture there may 

 protrude about sixteen tentacles, which are as long as the head. Neck short, as long as the head. First 

 segments much broader than long. Anterior segments slightly salient. All segments broader than long. 

 The posterior segments \viden and thicken suddenly, and are quite opaque. 



Habitat. — The spiral valve of Trygon kuhli. Forty -four specimens. 1910 and 1911. 



Trematode (?), sp. (Plate III., Fig. 41.) 



During the examination of a number of specimens of Diagramma crassispinum, thi'ee specimens 

 were found to contam a most remarkable free living parasite in the coelom. 



Unfortunately I have not had the time to make a careful examination of this parasite, and lam 

 at present micertain of its strict zoological position. The worm is to all appearance a huge Trematode. 

 Jn the living condition it measured 15 inches long and IJ inch broad. It was quite flat, and had a thick- 

 ness of ^ inch. The preserved specimens, of which I have three, measure 9 J inches long, | mch broad, 

 and are about | inch thick. Tlie extremities are rounded, and terminate in a minute acute point. At 

 one extremity there is a minute sucker-like aperture situated centrally, whilst at the other extremity there 

 is a similar but slightly larger aperture situated laterally. Tliis latter aperture appears to open to the 

 interior of the worm. The edges of the worm are straight and parallel. A pair of narrow blackish tubes 

 rmi along the lateral margins — one on each side. Down the centre of the worm, and stretching from 

 one extremity to the other, is an opaque milky-white mass |- inch broad. On each side of this mass there 

 are a series of black coiled tubes jV inch m diameter disposed in bunches, also ruiming the entire length of 

 the worm, but situated for the most part on one side. The rest of the worm is quite transparent. 



No other apertures could be detected. In consistency the worm is that of a stiff jelly. 



A full description of this enormous parasite, which is m all probability a Trematode, \vill be published 

 as soon as the anatomical details have been worked out. 



Habitat. — The body cavity of Diagramma crassispinum. Tluee specimens, only one in a fish. 

 February, 1911. 



I append herewith a list of parasitic material collected in Ceylon from various sources during the 

 ])ast few years. The list comprises all the cestodes I have up to the present collected from the marine 

 fishes of Ceylon. 

 57-11 



