1 1 88 BULLETIN OF THE BUREAU OF FISHERIES. 



increases slightly in breadth for about one-quarter of the entire length and 

 then tapers gradually to the posterior end, which is rounded off. The body 

 is elliptical in cross section without any segmentation, but with numerous rather 

 prominent annular wrinkles. It seemed as if the margins of the body were 

 thicker than the center. The head was retracted. (Fig. 7 and 8, pi. cxxi.) 



The second specimen (fig. 9 and 10, pi. cxxi) was found free in the body 

 cavity of another salmon. It was 36 mm. long and 0.86 mm. in breadth. The 

 body was somewhat thicker than in the other specimen, but less deeply wrinkled, 

 and the center was certainly thicker than the margins. In this, as in the color 

 and texture, it appeared different from the first specimen. There was no neck. 

 The head measured 0.31 mm. in transverse diameter and 0.43 mm. from the 

 apex to the base of the grooves, which were keyhole shaped. The groove 

 measured 0.25 mm. in transverse diameter at the anterior end and 0.09 near 

 its posterior end. In spite of the differences in appearance noted above it is 

 easily possible that the two specimens belong to the same species and I have 

 preferred to list them for the present under a single heading, naming the form 

 Sparganum sebago. 



A word should be said with regard to other ho.sts for these cestodes. 

 Abothrium crassum was not found in any other fish examined at Sebago Lake. 

 Larv£e of Proteocephalus and of some bothriocephalid were found in a very few 

 cases in other fish taken from these waters. There were none, however, of 

 which it could be said with reasonable certainty that they were the same as the 

 forms collected from the Sebago salmon and mentioned above. The question 

 of the occurrence of such salmon parasites in other hosts of this region must be 

 left entirely open for the present at least. 



NEMATODES. 



Nematodes were not common. The}' occurred only in half of the specimens 

 of salmon examined and were not abundant. In one salmon 33 of these worms 

 were obtained, but in the other three only a dozen all told. Accordingly they 

 seem to play only a minor part in the parasitic fauna of the Sebago salmon. 

 They belong to two or three separate species, which are radically distinct. Thus 

 far I have not been able to make a satisfactory determination for any of them, 

 owing to the scantiness of the material and to its unsatisfactory condition. 

 This much can be said: They do not belong to any of the species, or even to 

 the genera, heretofore recorded for the Atlantic salmon. A few notes may be 

 added here concerning these forms. 



A small nematode was found in the stomach and in the body cavity of two 

 salmon. In all there were only six individuals of this species. I have not been 

 able to satisfy myself that the individuals recorded as from the stomach 

 really belong there, but incline to think that they were adherent to the external 



