790 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [72] 



The following data are from the larger lot aud heuce represent more 

 general characters. 



The meshes of the reticulations on the face of the bothria are about 

 Q4u.n1 j L1 diameter. The effect of this reticulation, of the crenulated bor- 

 der, of the marginal row of loculi, and of the ramifications of the water 

 vascular system on the transparent bothria of the living worm is very 

 striking. It is a very beautiful object indeed. The loculi on the bor- 

 ders of the bothria in alcoholic specimens measure .05 by ,07 mm , outside 

 diameters, and .03 by ,04 mm inside. The auxiliary acetabulum, while 

 usually visible on the anterior edge of the bothria of living specimens, 

 is often found only with great difficulty in the alcoholic specimens. 



There is really no head, properly speaking. The neck simply be- 

 comes a little broader towards the anterior end and bifurcates, thus 

 forming the two fleshy columns or pedicels which support the marginal 

 pairs of bothria. In the alcoholic specimens the bothria are somewhat 

 contracted and the pedicels shortened, so that the head loses something 

 of its distinctively bilobed appearance and in lateral view appears to be 

 transverse, making with the neck a figure like the letter T. The cren- 

 ulated borders are much folded and crumpled. 



The character of the neck is much the same in all as in the specimen 

 already described, except that the four large aquiferous vessels which 

 lie in pairs about midway between the median line and the margins 

 are usually sinuous. In general the neck is flattened and rather broad 

 near the head. It soon grows narrower and for some distance is nearly 

 cylindrical. In the living specimens the surface appears to be perfectly 

 smooth for the first 7 to 12 mm , at which point fine transverse lines are 

 discernible, which a little farther on give rise to the first segments. 

 In the alcoholic specimens, however, fine transverse lines occur imme- 

 diately behind the head. 



At the point where the segments begin there is, in the living worms, 

 a slight enlargement of the neck, at which point, in some, the inner tis- 

 sues of the neck appear to end abruptly in a rounded stopper-like ter- 

 mination, which, like the neck proper, is more transparent than the 

 body which follows. This abrupt transition from neck to body is not 

 so apparent in the alcoholic specimens, but in all there is a rather 

 sudden enlargement about the point where the first segments begin. 



When these worms were placed in Perenyi's fluid they contracted to 

 nearly one-half their length in sea-water, and with few exceptions as- 

 sumed a highly characteristic shape. The head is contracted, loses 

 its forked or bilobed appearance, and viewed laterally is oblong and 

 placed transverse to the neck. The latter is rather narrow, cylindrical 

 for about 8 nim , when it enlarges rapidly and merges into the body. The 

 maximum breadth is soon attained, and for some 12 """, more or less, 

 varying with the size of the specimen, remains of nearly uniform size. 

 The breadth is apt to decrease slightly with the maturing segments. 

 The latter are squarish. The specimens which have many mature seg- 



