loi ]\Ir. ^X. NicoU on Trcmatode 



K. bacillus *, E. apinulosum f, E. echiiwium X) ; for instance, 

 the anti'i-ior ridge with itsspincsj which ditt'cr only in number 

 and arrangement, and the positions and rchxtive sizes of the 

 suckers. It may be ehisscd under this subgenus and is 

 probably a new species ^. 



Ou further examination and disseetion of the organs and 

 tissues of the cockle, a number of ciliated sporoeysts || 

 (PI. IV. fig. 7) were found, chiefly in the liver, but sometimes in 

 connexion with the intc^stiue — occasionally in both places in 

 the same individual. Karely were there more than half a 

 dozen in one cockle, and oidy in about 20 per cent, were 

 they entirely absent. They seemed to be free, and being 

 provided with cilia they moved about actively enough. The 

 general outline of the body was oval, tapering anteriorly, but 

 somewhat blunter posteriorly. There Avas some diversity in. 

 size, the largest being about "8 mm. long, with a greatest 

 width of '38 mm. Small examples not exceeding '2 mm. 

 ■\A ere occasionally observed. 



Two crescentic eye-spots (fig. 7, e.s.) are present in front, 

 and between and slightly anterior to them a pharynx is 

 situated. Inside the sporocyst a number of globular cysts 

 appear, usually from six to eight. Each cyst contains from 

 two to four daughter-sporocysts (d.s.) in various stages of 

 development. The youngest cysts, occurring generally near 

 the body-wall of the sporocyst towards the anterior end, 

 appear entirely undivided and contain small globular bodies. 

 A somewhat older stage shows a division into two hemi- 

 spheres. Later these take on the character of daughter- 

 sporocysts, two eye-spots and cilia making their appearance. 

 Towards the hinder end of the daughter-sporoeyst four or 

 five globules are seen similar to those mentioned above. 

 Inside the cyst the minute sporoeysts can be observed moving 

 round and round, and on rupture of the parent they make 

 their escape and swim about with considerable agility. 



The relationship of these sporoeysts to the other stages of 

 Trcmatode larvre found in the cockle is a matter of some 

 difficulty. The occurrence of the sporoeysts, containing 

 cercariae, in close proximity to the liver is somewhat sug- 

 gestive of a connexion between these two stages at least. 



* V. Linstow, Arch. f. Xaturg. xliii. 1877, p. 183, pi. xiii. fig. 15, 



t Ibid. fi-r. 14. 



X Wedl, Wiener Sitzuufcsber. xxvi. 1857, pi. i. fig. 5. 



§ Cf. Northuruberland .Sea-Fiisherit's Ke}ioit, 1004, p. 82, where, in a 

 note by Mi.ss M. V. Lebour, B.Sc, what appears to be the same parasite 

 is described, but in an imperfect manner. 



ij The spurucjsts are also described in the same note. 



