[27] * NOTES ON ENTOZOA OF MARINE FISHES. 745 



ment, now on one side, now on the other, with a tendency for several to 

 succeed each other on the same side. The cirrus arises from a pear- 

 shaped pouch, whose walls are composed of fine interlacing contractile 

 fibers.. In most cases the cirrus is retracted and lies coiled up withiu the 

 pouch. The larger end of the pouch is directed towards the median 

 line, at its base lies the vas deferens in a voluminous mass. The testes 

 occupy considerable space. The large granular masses, of which they 

 are composed, are most abundant towards the margins, where they fill 

 the central parts of the proglottis. Towards the middle of the prog- 

 lottis they are displaced by the female genital organs. 



The ovaries are situated near the posterior edge of the proglottis 

 near one of the lateral faces, which, for convenience, I will call the 

 ventral face. The ovary itself viewed laterally is an oblong, many lobed 

 organ, made up of globular, nucleated cells, some of which measured 

 from .008 to .013 mm in diameter. The ovary in its widest place equals 

 about one-third the breadth of the proglottis, and is about one-half as 

 long as broad. Its average depth in the specimens measured is less 

 than .2 mm . From its anterior part the vagina arises and passes outwards 

 towards the margin, then ascends dorsally on a level with the cirrus 

 pouch, the dorsal edge of which it follows closely. It opens near the 

 small end of the cirrus bulb, so that the two organs, cirrus and vagina, 

 have a common cloacal opening on the margin of the proglottis. The 

 position of the vaginal opening was demonstrated only after long and 

 careful search. The oviduct originates at the anterior part of the ovary 

 and is continued into a long and much convoluted tube, which in all the 

 segments, except those that constitute the anterior slender part of the 

 strobile, contains numerous amber-colored eggs. 



Before sections were made, ova were seen in little clusters on one of 

 the lateral faces of the body. When section s were made it was discovered 

 that these pores not only actually exist, but that they are of invaria- 

 ble occurrence on the mature segments. They are not in any seuse 

 caused by a rupture of the wall of the proglottis, but are definite aper- 

 tures. They lie on the ventral side, that is, the same side of the prog- 

 lottis as that on which the ovary lies, and near the anterior edge, a lit- 

 tle to one side or the other of the median line. They thus form an 

 irregular zigzag line along the middle of the ventro-lateral face. The 

 oviduct communicates directly with this excretory pore. Mature ova 

 were found in what appeared to be rather immature segments. A shell- 

 gland was demonstrated, somewhat doubtfully, however, in front of the 

 ovary. The egg-inflated oviduct so crowded the middle space of the 

 segment as to render it very difficult to make out the relations of the 

 various parts. 



It is to be noted that there is no really clear dividing line between 

 the segments when seen in longitudinal section. The relationship of 

 Dibothrium to Ligula is thus clearly demonstrated. 



