774 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [56] 



broad at base. Tliey are straight, with sharply recurved and hooked 

 extremities. 



I have not yet succeeded in making out the other genital organs 

 with entire certainty. The sections show near one of the lateral faces 

 a number of irregular masses, which, from their striated appearance 

 and absence of stained nuclei, I suspect to represent the convoluted 

 vas deferens. Toward the interior of the segments these give place 

 to irregular granular bodies from .02 to .04 mm in diameter, which fill 

 the interior of the segment around the muscular cirrus sheath. These 

 bodies evidently represent the spermatic capsules of the testes. I find 

 no traces of even the beginning of female genitalia in these segments. 



Transverse sections of the head show that the loculi are formed by a 

 dense layer of parallel radiating fibers, which is very sharply defined 

 from the deeper tissue of the bothria. This layer is about .05 mm thick 

 at the bottoms of the loculi, but is somewhat thinner at the edges. 

 It appears to consist of columnar epithelium. Where two loculi join, 

 this layer of radiating fibers in each rises to form the separating costa. 

 The transverse section of a costa therefore shows it to be composed of 

 two layers which are confluent at the outer edge. This radiate fibrous 

 tissue contains a few scattered granules, which, although very small, 

 in several instances proved to be distinctly nucleated. The radiating 

 fibers of the bothria themselves originate from a thin layer of fine 

 fibers, which in many places seems to have separated from the tissue 

 beneath, but which, in normal position, rests on a layer of coarse longi- 

 tudinal fibers in the center of the bothria. Towards the edges of tin 

 bothria the coarse longitudinal fibers disappear and the layer of radia- 

 ting fibers is succeeded by the outer granular tissue of the head, in 

 which there are a good many longitudinal fibers. 



Four principal vessels are cut by these cross-sections. Of these, two 

 lie near tbe center of the head and are .015 mm and .02 nim in diameter, 

 near the middle of the length of the head. The others are larger, ob- 

 long, and are situated near the margins. Near the middle of the head 

 the iuside diameters of one of the marginal tubes were .025 and .01G mm , 

 the outside diameters .032 and .038 mm . These dimensions are some- 

 what exaggerated since the sections were carried a little obliquely 

 through the head. 



Transverse sections of the neck reveal the same alternation of mus- 

 cular layers as noticed in the segment. The fascicles of the thick layer 

 of longitudinal muscles are oblong in section and are disposed radially 

 around the central space. This layer is interrupted for a short distance 

 at the margins, where the granular central space is continuous with the 

 granular layer, outside the fascicular layer. 



In some sections there are three, iii others there appear to be four, 

 vessels near the margins. Two of these are larger than the others. 

 The outer one of these two, that is, the one nearer the margin, has a 

 definite limiting wall, while the other is more irregular in outline am 



