PLATE II. 



LOPHOPUS CRYSTALLINUS. 



Fig. 



1. Loj)hopus crystallinus ; specimens attached to tlie roots of Lemna poli/rJiiza. Natural 



size. 



2. The same enlarged ; adult specimen. 



3. The same ; young specimen, with two polypides. 



4. Statoblast q{ Lophopus crydallinus, magnified about 50 diameters; viewed in face. 



5. The same, viewed on the edge. 



6. Portion of internal or hepatic layer of stomach. 



7. Three isolated cells of this layer further magnified. Each cell is seen to contain within 



it a secondary cell, with brown contents. 



8. Middle layer of stomach, composed of cells with colourless contents, and brilliant nucleus. 



9. Structure of the endocyst ; the tissue has been treated with acetic acid, and presents 



isolated nuclei, and nucleated cells in various stages of formation. 



10. Muscular network of the endocyst. 



11. Muscular fibre from the endocyst more highly magnified, and treated with acetic acid. 



12. An isolated muscle-cell of the same, still more highly magnified. 



13. Tubular network, containing peculiar corpuscles, occasionally seen in the substance of 



the endocyst. 



14. Corpuscles of the tubular network isolated. 



1 5. The same, under the action of acetic acid. 



16 — 23. Parasitical organisms from the perigastric fluid of Lophopus crydallinus. 



24. Semi-ideal view of part of the lophophore and tentacular crown oi Lophopus, showing the 

 mouth and neighbouring parts, with the distribution of tiie nerves. The tentacula 

 are partially removed, so as to bring into view the >ipper surface of the lophopiiore. 



