676 A NEW BNIJOPARASITIC COPEPOD, 



The body-cavity (hsBmocoel) is more or less filled by branched, 

 connective tissue cells, in some places more so than others. Cor- 

 puscles of two kinds are present in the coelomic fluid ; small, spheri- 

 cal, hyaline corpuscles about 3/i. in diameter, with intensely stain- 

 ing nucleus, and larger forms with more opaque cytoplasm and 

 vesicular nucleus, and varying in size from 8 to 15/jl. These latter 

 are irregular in outline, and are probably amoeboid. 



From place to place along its length, the alimentary canal is 

 slung to the dorsal and ventral body-wall by bundles of clear fibres 

 of some thickness (about Ijjl), which closely resemble plain muscle- 

 fibres, but are devoid of nuclei. 



Alimentary Canal. — Within the mouth is a small chitin-lined, 

 buccal cavity (Fig. 15), from which the oesophagus passes directly 

 dorsad (Fig, 2), to the centre of the body, and there opens into the 

 digestive tract, which, divided by three constrictions into four com- 

 partments, extends backward in a straight line through the trunk, 

 and ends blindly a short distance posterior to the genital apertures 

 (Fig.l). 



Immediately within the oral aperture is a sphincter muscle, and 

 radiating to the body-wall and endoskeletal rods previously men- 

 tioned are six strands of muscle, constituting together a dilator 

 oris. These muscles are striated (Fig. 12). 



The oesophagus is lined by a columnar epithelium, whose com- 

 ponent cells are, for the most part, completely hyaline, some, how- 

 ever, having granular cytoplasm (Fig. 16), 



The general arrangement and relative size of the various com- 

 l)artments is sufficiently evident from the diagram (Fig. 1) and 

 transverse sections (Figs. 20 to 25) ; it remains to describe the epi- 

 thelium Iming it, and a peculiar digestive ( f ) gland secreting into 

 the second compartment. 



The anterior portion of the first compartment is lined by an 

 exceeduigiy irregular epithelium, depicted in Fig. 19. The cells, of 

 extremely variable size, have a very granular cytoplasm, the granu- 

 larity being variable. The largest granules (zymogen) are found in 

 the enlarged bulbous ends of the larger cells, and are apparently 

 shed by actual abstriction, since structures precisely similar to the 



